Planning a Homes Location

When Choosing a Home Site
Take the High Ground!

When choosing a lot or placing your new home on the site, it is usually advantageous to pick the highest point that is practical. If selecting a lot in a relatively flat subdivision try to get one near the top of the grade if at all possible. It is no accident that the "house on the hill" is usually the most expensive in town! This is partly due to the view, but also the fact that they will have no drainage problems even if the rest of town is under water.

There are numerous subdivisions being built on property that has never had any flooding or drainage problems. These same subdivisions often have major flooding problems within just a few years mainly because of overbuilding. Buildings, streets, driveways, sidewalks and patios all contribute to the problem by diminishing the area of land that rain water can seep into.

Municipal storm sewers can alleviate the problem but municipalities in growing areas often have not planned far enough ahead to control it properly. This could mean that your property taxes may have to be increased by substantial amounts, perhaps double or triple, as the local governing body finds that they must tear up fairly new streets and sewers and replace them with more capacity.

Either that or face the wrath of new homeowners that have their life savings in a home with 2 feet of water in the basement and 6 inches in the garage. It is a good idea to drive around the neighborhood where you are considering to build during, or immediately after an especially heavy rain.

Site Considerations

1. Neighborhood. Are the properties well maintained? Check proximity to schools, recreation, shopping etc.

2. Zoning restrictions and/or moratoriums on building. Visit your local building department. Check for easements.

3. Drainage. Is the property in a flood plain or on wetland? Soil erosion?

4. Soil type, especially if the property does not have municipal sewer and water.

5. Is there well water likely to be found at a reasonable depth?

6. Is it feasible to have a septic system and a viable well on this property?

7. Is there a homeowners association with many restrictions on use? The real estate agent should know.

8. Covenants, deed or otherwise. (Closing documents)

9. Public and utility easements. (Plat of survey)

10. Taxes and impact fees. (Zoning department)

11. Access to the property.

12. Will the soil support a foundation?

13. Topography, trees and other vegetation.

14. Do you want to live in the city, country or suburbs?

15. Amenities of the community, such as schools, fire & police protection.

16. Is the community building new schools or other public works that will mean higher taxes.

17. Will the sun be blocked by buildings? What is the view?

18. Is there room for future expansion?

19. Are there plans for a nearby airport or new highways?

Determine that your site is suitable for building. Your local health or building department should be able to tell you if it is feasible to have both a well and a septic system on a particular piece of property. This may require a soil test and/or other studies.

If your lot is within a municipality, the local building and zoning department will likely have this information. Excavating contractors should also know what the soil conditions are. By the same token, a local well driller will probably have a good idea of how deep a well is required for your location. Contractors are an excellent source of technical information.

Also consider any special excavation conditions that may be encountered. Determine where you will access the property and where you will locate the house, garage, well and septic system. If there is municipal sewer and water, where does it enter the property? Be sure to verify with the proper authority where you will be allowed to access the road, (place your driveway). Plan a turnaround of some sort, especially if you live in snow country.

You must also consider the environmental impact of your building. If you have a low lying lot that collects water after a rain you will need to find a way to drain it. Do not assume that you can just haul in enough fill and build up your lot to drain the water off. Your neighbors may have some choice thoughts about that!

Very few, if any, local governing bodies will allow you the change the environment in that manner. Even if you get away with it, the owners of the neighboring property would probably sue you, even if it is vacant land. You do not need that kind of aggravation, and besides, you may lose in court. (It won't make you any friends either.)

In order to get a building permit, you will probably need a plat of survey by a licensed surveyor. Check with the previous owners as they may already have one. It may have been included in the closing documents.

Once you have done all of the above you can decide on the the exact location of your home on the lot, and the style of house that best suits the lot and neighborhood you have chosen. Be sure to consider the impact of tree removal if necessary. Local regulations may govern this.

Home Inspection

System For Home Inspection

Although architectural details, wall and floor coverings, modern conveniences and many other factors are important in the buying decision, the focus of this inspection is on the structural/mechanical/electrical condition of the property.

The house inspection is designed to give the real estate agent or prospective purchaser a system to detect some of the readily accessible major flaws or deficiencies in the significant components and systems of a home. It is not designed to, nor does it profess to facilitate detection of all flaws, problems or occurrences that might exist in any given home.

To maximize time efficiency and to ensure all of the major sections of the home are take into consideration, we have developed a systematized approach to the inspection. This is a simplified overview of systems that professional home inspectors use when they are inspecting a home.

To assist you in following the system, we have provided a checklist that will guide you through your own house inspection.

General Inspection

The first step in inspecting a home is to examine the big picture for the home. Notice the area the home is located in. Are there other homes of similar age and construction details relative to the home you are inspecting? A comparison will give you a general idea of the upkeep of the home. Have there been significant modifications to the exterior of the building and if so, how is the workmanship?

Exterior Inspection

Start at the exterior front of the house and work your way around the house (clockwise or counter-clockwise) at a distance which allows you to view a complete face comfortably. On each face (front, sides, rear) start your visual inspection at the top of the structure and work your way down to the ground and lot area. As an example, you would start at the front and note the roof and chimneys, the gutters, fascia and soffits.

Then, moving down the exterior wall coverings (brick, wood, aluminum), noting windows, doors, etc. Examine any porches or decks down to the foundation, then the grade or slope of the lot area, followed by any coverings, such as flower beds, walkways, interlocking brick, driveways, etc.

Move nearer the house, to examine more closely any details which may have attracted your attention, without skipping any items. Having completed the front, move to the side of the house and start the same procedure (roof to ground)

Interior Inspection

On the interior, begin your house inspection in the basement and then follow the system throughout each floor in the house. The system for inspecting the interior is to begin with the floor, go to the walls and then the ceiling, and then consider any appliances or other items in the room. Move from room to room, always in the same direction (clockwise or counter-clockwise) so as to not miss any areas. If you see a door, open it!

In the utility room in the basement, first notice the floor, the walls (possibly the foundation walls are visible here), then the ceiling (floor joists may be visible), then go to the furnace, hot water heater, electrical panel, plumbing system, etc. When inspecting the floors, walls and ceilings, scan the entire area that is visible, not just one section.

In a finished room you would notice the floors, walls (including windows) and ceiling. Next look for the heat sources, electrical outlets and switches, fireplaces, closets etc. In bathroom or kitchen, notice the floor, walls and ceiling, then the plumbing fixtures.

Home Condition Inspection

While performing the home inspection, whether at the exterior, the interior or one of the mechanical systems, note the system first, then its relative condition. For example, if you were inspecting a wall on the interior of the home you would first note that the wall is plaster, and then examine the wall for cracks and irregularities.

Problems

The following are some typical problems or occurrences to look for in the major components and systems of the home:

Problems With Roof
Is the ridge (peak) showing a sag, or is it straight and level?
Is the roof sagging between the rafters or trusses?
Are there any signs of deterioration of asphalt shingles, such as curling, wasping, broken edges, rounded corners or key holes (slits) becoming wider that normal?
Are there any loose flashings, at the chimney, roof-to-wall connection or elsewhere?
Does the wooden roof deck appear rotten or delaminated under the last row of shingles?
Are there any roof vents visible?

Problems With Chimneys
Is the masonry cap cracked or broken? Are any bricks flaking or missing? Is any mortar missing? Is the chimney leaning?

Problems With Soffits and Fascia
Note whether the soffit and fascia are wood, aluminum or plastic Any loose or missing sections?
If wood, are there any paint problems? Any visible rot?

Problems With Gutters and Downspouts
Ensure gutters slope down toward downspouts- is there any rust or peeling paint?
Are there apparent leaks or loose/sagging sections?
Are the downspouts extended away from the foundations?

Problems With Wall Coverings
Look for missing mortar
Are the bricks flaking or cracking?
Look for loose, missing or rotten siding, deteriorated paint.
Does the siding appear new? Does it hide the foundation wall?
Are the exterior walls bowed, bulged or leaning?

Problems With Windows And Doors
Look for problems with paint or caulking, and rotted wood components. Are the windows new or older? Are they the original windows?
Problems With Porches and Decks
Cracking or flaking masonry?
Check for paint problems, rotted wood, and wood-earth contact.
Note any settlement or separation from the house.
Inspect the underside, if accessible.

Problems With Foundations
Check for cracks, flaking or damaged masonry.
Note any water markings and effluorescence (whitish, chalky substance) Any bowing, buldging or other irregularities?
Soft mortar?

Problems With Lot Area
Does the grade slope away from the house?
Any settled/low areas next to the foundation, or cracked walks/driveway? Is the property lower than the street or neighboring properties?

Problems With Basement
Note any evidence of water penetration (stains, mildew/odors, effluorescence, loose tiles etc.)

Problems With Floors
Check for deteriorated coverings or cracked ceramics. Any water staining or other damage? Sloping or sagging?

Problems With Walls
Randomly sample to check that the windows and doors work. Are the walls straight vertically and horizontally? Look for cracked or loose plaster. Look for stains, physical damage or previous repair evidence. Any drywall seams or nails showing?

Problems With Ceilings
Check for cracks in the plaster or loose, sagging plaster. Look for stains, mechanical damage or evidence of previous repair. Seams or nails showing?

Problems With Bathrooms And Kitchens
Check that all fixtures are secure. Are there any cracks in the fixtures? Note the conditon of the tiles and caulking in the tub/shower area. Are the faucets working? Do they leak? Sufficient water pressure? Look for staining and rot under the counter-tops Randomly sample the operation of the cabinet doors and drawers.

Electro-Mechanical Considerations
Type, style and age of heating & cooling systems. When were they last inspected or serviced? Type of water supply piping and drains - any visible rust and corrosion? Size and age of electical service - are the outlets grounded? Visible wiring in good condtion? Have there been any upgrades?

Read more: Home Inspection - A Checklist For Common House Problems
http://www.whatprice.co.uk

Passive Solar Technique: Let Nature Heat Your Home

Categories: Green Building

 

Homeowners are increasingly worried about their dependence on fossil fuels. They’re also more and more intrigued by the information about solar energy. Why? Because it saves money, benefits the planet, and makes for a comfortable house that requires little in the name of back-up fuel.

James Kachadorian, civil engineer and founder of Green Mountain Homes, has all the information a homeowner needs in order to implement a passive solar house. Read on!

The following is an excerpt from The Passive Solar House: The Complete Guide to Heating and Cooling Your Home by James Kachadorian. It has been adapted for the web.

During the summer of 1973, the U.S. economy was booming. We were all whizzing down the highway at 70 miles per hour, the legal speed limit. Gasoline was about 39 cents per gallon, and the posted price of Gulf crude oil was $2.59 per barrel. That year, my wife Lea and I had purchased a lovely old Vermont farmhouse, heated by a coal-stoking boiler that had been converted to oil. The base of this monster boiler was about three feet by six feet, and when it fired, it literally shook the house. We tapped our domestic hot water directly off the boiler, so we had to run the unit all four seasons: Every time we needed hot water, the boiler in the basement fired up. We were burning about 2,500 gallons of fuel oil each year, and in the coldest winter months, it was not unusual to get an oil delivery every two weeks.

Since we had no other way to heat our home, we were entirely dependent on the oil-gobbling monster, and on our biweekly oil deliveries to survive the Vermont winter. Our only alternative source of heat was an open fireplace. Though aesthetically pleasing, the fi replace actually took more heat out of the house than it gave off.

At that time, I was the vice president and general manager of a prefabricated post-and-beam home operation. Like others, I shared the industry opinion that the heating contractor’s job was to install the heating system that the homeowner wanted. As designers and home producers, we were not responsible for that part of new home construction. Home building plans were typically insensitive to the position of the sun. Our prefabricated home packages were labeled simply “front, back, right side, left side,” not “south, east, west, north.” We offered little or no advice on siting, except that we needed enough room to get a tractor-trailer to the job site.

To give you an idea how little energy effi ciency was considered in 1973 in house design (an area of home construction that has since received enormous attention), our homes had single glazed windows and patio doors; R-13 wall and R-20 roof insulation were considered more than adequate. (“R” is the thermal resistance of any housing component; a high R-value means a higher insulating value. Today’s homes typically have much higher R-values.) Homeowners in the 1970s rarely asked about the R-values of their home components, and our sales discussions were less about energy efficiency than about how the house would look and whether it would have vaulted ceilings.

The point is, we were not yet approaching the task of design and construction in an integrated, comprehensive way. We had not yet recognized that all aspects of a design must be coordinated, and that every member of the design team, including the future resident, needs to be thinking about how the home will be heated from the first moment they step onto the site.

THE OIL CRISIS

In 1973, an international crisis forever changed the way Americans thought about home heating costs. After Israel took Jerusalem in the “Six Day War,” Arab oil-producing nations became increasingly frustrated with the United States’ policy toward Israel. In the fall of 1973, these oil-producing nations began to utilize oil pricing and production as a means to influence international policy. In October 1973, the Organization of Petroleum Exporting Countries (OPEC) met and unilaterally raised oil prices 70 percent. The impact of this price hike on U.S. homeowners who heated with oil was spectacular. Fuel oil prices soared.

Then the oil embargo hit. In November 1973, all Arab oil-producing states stopped shipping oil to the United States. By December 1973, the official OPEC member-price was $11.65 per barrel—a whopping 450 percent increase from the $2.59-per-barrel price of the previous summer. Iran reported receiving bids as high as $17.00 per barrel, which translated to $27.00 per barrel in New York City.

In addition to giant price increases, oil supplies became uncertain and the United States, which depended on foreign oil for fully half its consumption, was facing the real possibility of fuel rationing for the first time since World War II.

Richard Nixon was president, and his Secretary of State, Henry Kissinger, spent most of that winter in what was termed “shuttle diplomacy,” racing from country to country attempting to bring a resolution to the crisis. He didn’t succeed until March 18, 1974, when the embargo against the United States was lifted. It had lasted five months.

As the international oil crisis was played out over those five months, every oil delivery to our home was marked by a price increase, invariably without notice. Worse, our supplier could not assure delivery. My wife and I had two small children, an energy dinosaur of a house, and no other way to keep warm but to burn huge amounts of oil. We couldn’t even “escape” to a warmer climate, because there were long lines at the gasoline pumps. We had never felt so dependent on others as we did that winter. It was plain scary!

We have done a little better recently, as today only one-fourth of U.S. oil comes from OPEC. Most imports come from more stable Western sources, and are so diversifi ed that a full-scale war in the Persian Gulf in 1991 caused
no gas lines at home. However, we are still over 50 percent dependent on foreign oil sources.

All the concerns about energy seem to have reached a boiling point in September and October 2005. Back-to-back hurricanes in the Gulf region of the United States crippled our refining and fuel distribution capabilities, and oil and propane gas soared to new record highs.

THERE HAD TO BE A BETTER WAY

I have a background in engineering, and the energy crisis of 1973–1974 provided an incentive for me to investigate solar heating. It was obvious to me that as a country, we had forgotten the basics of good energy management. I just knew that there must be a better way to design and build houses that would capture the sun’s heat and work in harmony with nature. I also have a background in business, and I realized that the energy crisis had opened up a market ready for new ideas about how to heat homes. The energy crisis had shaken us all into action.

The years immediately following the 1970s energy crisis saw a remarkable emergence of new ideas about solar energy. Solar conferences were held, and the public was treated to frequent articles that described new solar home designs in popular magazines. The results of this collective effort were largely positive. Many new ideas were tested. Some succeeded, and others failed, but building specifications focused on energy efficiency developed during that time have now become standard practice. For example, double-pane high-performance glass is now used almost universally in windows and patio doors. Standard wall insulation is now R-20. That was previously the roof standard; standard roof insulation is now R-32. The science of vapor barriers took huge leaps forward, and highly effective vapor barriers are now standard. Exterior house wraps, such as Typar and Tyvek, are applied on most new construction to tighten up air leaks. Appliances are now more energy efficient. Heating systems have undergone major improvements. These days, it is even common for “smart houses” to monitor lighting and to turn lamps and heating equipment on and off according to need. In sum, we are now building better energy-efficient houses, in large part due to the wake-up call we got in the winter of 1973–1974.

Patterns of Home

Technorati Tags: pattern of house,siting of house

Pattern Four — Capturing Light : A House that Follows the Sun

The Jacobs family house on a bluff in Rhode Island by architect Tut Bartzen.
Photo: David Duncan Livingston

The owners wanted a practical house, one that took full advantage of the light and the spectacular views and one that allowed ease of movement from indoors to out. In keeping with its New England setting, the basic form of the house is straightforward — a two-story rectangle with cut-away chamfered corners facing south.

The house is carefully positioned on the site. By setting the house with its leading corner facing south, two full sides of the building receive south sun, filling the interior with light from morning until night.

A wide porch with a balcony above wraps the south corner, inviting an easy flow from the living room, entry, and bedrooms out toward the view.

The porch roof provides natural seasonal light control for the lower floor, limiting the entry of light when the sun is high in the sky at midday in summer. When the sun is lower in the sky — early morning and evening, winter, spring, and fall — the angle allows light to penetrate the porch and enter the rooms beyond. As the day or the season gets cooler, the sunlight reaches deeper into the house.

Upstairs, each of the three bedrooms has windows to the east; as the sun comes up it gradually fills the rooms with light, waking the occupants gently. Each bedroom also has windows on a second wall, balancing the light in the room and increasing the period of direct sunlight. By mid-afternoon, the bedrooms are protected from heat gain by the placement of the bathroom and fireplace to the west.

Siting the house diagonally to the south takes maximum advantage of available sunlight. Every room gets direct sun at some point during the day.
Image: Taunton Press

The high living room ceilings allow space for transom windows above the glazed doors and windows that fill walls on three sides. The bright, open space changes mood as the sun moves from east to west.
Photo: David Duncan Livingston

Jabobs House, ground floor.
Image: Taunton Press

Jabobs House, upper floor.
Image: Taunton Press

Click on thumbnail images to view full-size pictures.

At breakfast, the eastern sunlight enters the kitchen and adjoining dining room. Diners start the day with the early warmth of morning sun balanced by light from the kitchen window to the south.

By noon, the warm midday sun strikes the south face of the building, with its chamfered corners oriented to the view. A long wraparound porch shades the south side on the lower floor, giving midday protection to a kitchen window that fills the south-facing wall and to the French doors that open from the living room to the porch.

By late afternoon, the sun has moved around to the west and enters through the corner windows of the living room.

It is important for afternoon and evening activities to have a sense of the light but also to be protected from heat gain. Here the protection is created by dense landscaping outside the corner windows, which blocks the sun as it gets low in western sky.

The west-facing corner of the stairwell landing has windows that bounce light onto the very center of the house, where it falls down the stairs and into the entry hall — a balance to the more direct western light.

Discuss this article in our Home Design Forum...

Patterns of Home

Part of the ArchitectureWeek Patterns series. Text and images excerpted with permission from Patterns of Home: The Ten Essentials of Enduring Design by Max Jacobson, Murray Silverstein, and Barbara Winslow, copyright © 2002 The Taunton Press, Inc. The book is available from The Taunton Press and at Amazon.com.

Exterior House Painting Preparation - Introduction

Introduction, Difficulty Level and Needed Tools:
The most important step in exterior house painting does not involve a paintbrush but rather paint scraping tools. Preparing the surface prior to painting your home will make or break your paint job. It is rarely the paint film itself that fails but rather the adhesion of the paint to the surface below (often called "substrate" in painting lingo). The reason paint fails to adhere is because the surface to which it was applied was dirty, wet or was loose itself. So making sure your paint surface is clean, dry, free from grease, oils and flaking or loose paint will give your primer and paint a good surface from which to bond. Painting the exterior of your house over a dirty or poorly prepared surface is like building a house on a bad foundation, and that's never been a good idea.

Let's review the tools you'll need to get byour house ready for a paint job that will last many years.

* Difficulty LevelAverage (Laborious)

* Needed Tools and MaterialsPaint Scraper
* Putty Knife
* Sandpaper / Sanding Block
* Stiff Brush
* Heat Gun Paint Remover (possible)
* Power Washer (possible)

Site Analysis

Understanding all the features of a site, using and protecting the best, and minimising the impact of the worst.

Ground Stability

Proper investigation of ground conditions is a crucial part of the site assessment process. You’ll need good information about ground stability and bearing pressure to determine whether the site is suitable for building, where on the site to locate any building, and the type and size of foundations you specify for the type of construction proposed.

Cutting corners when assessing ground stability can lead to serious problems such as some degree of building failure. If in doubt, call in expert help from a structural or geotechnical engineer.
What to look for

In your site visit, consider:

* general landforms – can you see any clues which point to a risk of landslip, soil creep, or subsidence?
* what are the soil types present – some types of soil can bear more load than others, and some expand and contract with changes in moisture levels (see soil types below)
* drainage/runoff, water table, and presence of natural springs or waterlogged soils
* proximity to mine works, quarries, exposed banks and landfill sites
* bearing capacity of the soil
* presence of expansive clays.

Look out for warning signs such as:

* slumps/hollows
* cracks in the ground
* sudden changes in slope
* leaning fence posts, power poles and trees
* remnants of buildings
* hollows in the centre of a flat area of ground
* undercut banks
* banks cut steeper than the angle of repose for the soil type – repose angles are in the order of 33º for sand, 25-40º for dry sediment, 30º average for soil
* evidence of slips.

You’ll also need to consider past use of the site, including the possibility of buried structures, contamination, and earthworks and uncompacted fill that may affect ground stability.
Determining bearing pressure

The allowable bearing pressure of soil is a measure of its ability to carry the load of the building without excessive (more than 25 mm) settlement. Bearing pressure must be measured at the base of the foundations and will depend on soil type.

For buildings within the scope of NZS 3604 Timber-framed buildings the requirement is for an ultimate bearing pressure of 300 kPa. Indications of good ground include:

* the foundations of adjacent buildings are satisfactory
* there have been no landslips in the vicinity
* all fill complies with NZS 4431 Code of practice for earth fill for residential development
* there is no organic soil, peat or soft clay.

If the ground does not meet these requirements, a comparatively simple soil strength test method referenced in NZS 3604 using a scala penetrometer may be employed. See BRANZ Bulletin 438: Using a Scala Penetrometer for more information, or NZS 4402 Determination of the penetration resistance of a soil.

If it the ground does not comply, or the building is outside the scope of NZS 3604 you’ll need to have the ground condition verified by an engineer experienced in soil investigation.
Soil types
Peat subsoil

Peat, which occurs in low-lying areas, is compressed dead vegetable matter which has been preserved from decay by acidic groundwater. The surface of the ground may appear stable and dry, but the peat can be present in a deep layer which can compress appreciably under the weight of a building. If you suspect peat is present, you’ll need to consult a specialist soils engineer. The extent and depth of the peat will need to be determined by drilling a number of bore holes. Where the peat layer is thin it may be able to be removed to expose firmer soils below, or a specifically designed raft foundation and floor slab may be needed.
Sand

Sands vary in their particle size and in compaction. Some types of sand have low bearing capacity so you’ll need to use piles, driven down to a firmer layer, in conjunction with a specifically designed slab.
Expansive clay

Some soils contain substantial amounts of clay material, which increases markedly in volume when wet and shrinks when dry. Certain trees can add to the severity of shrinkage through their uptake of moisture.

If these soils may extend to a significant depth below the surface, and especially if they occur at a level where the water content fluctuates periodically, substantial uplift of the surface may occur during wet periods, followed by subsidence during a dry season. The amount of this uplift varies with the clay content of the soil but can be as much as 50 mm in some areas.

Remember that putting a building on a clay soil will change the moisture content, and result in a new pattern of expansion and contraction. Moisture content will also be reduced by large paved areas such as sealed driveways and patios, tree planting, and subsoil drainage.

The effect of the clay movement is influenced by the moisture content of the site at the time of construction. It is important that, once the excavation has been carried out, the slab is laid without delay to minimise drying out of the area which will be beneath the slab.

In areas of potential movement of subsoil, the use of rigid elements such as brick veneer and concrete block should be avoided unless the slab and foundations are specifically designed.
Fill

If the building site contains areas where the levels have been shaped by earth fill, either excavated from within the site or imported, it is important to ascertain that this fill complies with NZS 4431 Code of practice for earth fill for residential development.

A certificate showing compliance should be obtained. If such a certificate is not available, have tests done on the area to determine its bearing capacity and to ensure that it does not contain unsuitable material. If the bearing capacity of the fill is inadequate, the foundations must penetrate through to solid bearing.
Sloping ground subject to slipping

The stability of a sloping site is difficult to define. Slips can occur on slight slopes which have no obvious warning signs on the surface, particularly when soil becomes saturated. Look at the condition of similar slopes in the area, and also look for cracks, slumping, leaning trees, tilted fence posts and other evidence of subsidence.
Water table

A very high water table can lead to extra costs by making construction more difficult and because of the need for pumping of excavations and provision of land drainage to remove the water.

A high water table implies that water pressure in the soil is high, which means the soil will be correspondingly weaker. High water pressure will adversely affect the stability of any slope and increase the loading on the retaining structures. Certain types of expansive clay soil will increase markedly in volume when they are wet.

If the building site is surrounded by large areas of higher ground, underground water will tend to flow to the site. This may cause pressure beneath a concrete floor slab or increased moisture levels beneath a timber floor; it can drive water into timber piles. Subsoil drainage may be necessary.

Initial indications of a high water table include:

* reeds
* surface water or boggy ground
* springs.

The history of the site (obtained from documents such as the certificate of title) may confirm that the subsoil is suitable for the type of building proposed. If there is any doubt, its suitability can be established by digging trial holes.

For sites where a low rise building is proposed, digging some trial holes by a mechanical back hoe or by hand can provide useful information.

When digging trial holes, a record should be kept containing:

* date of excavation
* location of hole on the site
* relative level of hole if the ground is not flat
* overall dimensions and depth of hole
* excavation system used
* ease of excavation
* rainfall that occurred while the holes were being dug
* groundwater conditions and water table level (if found)
* soil descriptions and depth of each layer
* positions from which samples were taken.

During excavation of trial holes, precautions must be taken to support the sides of the hole so that it can be safely entered for taking samples. On completion, the trial hole should be backfilled by compacting the material in 150 mm layers so that future work in the area will not be affected.
Finding information

The first step in assessing ground conditions is to get the background information from the local and regional councils (see the site analysis checklist), the certificate of title and a site visit.

Wherever there are doubts about ground stability, always consult a geotechnical engineer.
For your clients

To help your clients understand the hazards that might affect a site and how to identify them, refer them to www.smarterhomes.org.nz/siting-landscaping/hazards.

Siting Guide For Your New House

Before you buy or build your new house please make sure of these tips below.

Say No to these:

1. Peat land (avoid flood, fracture, floor sinking)

2. Land slope more than 35 degree ( avoid landslide)

3. House distance less than 500 meter from any industry (produce noise, dust, bad smell etc)

4. House distance less than 500 meter from heavy traffic road (main road - avoid noise).

5. Nearest Street level higher than the house. (flooding, accident)

6. Study the previous land used and avoid these:

i. former mining land.(avoid fracture, floor sinking)

ii. former dumping site.(avoid fracture, floor sinking)

7. House distance less than 500 meter from sewage treatment system like septic tank, sewage ponding system etc.(avoid bad smell)

8. House distance less than 3km from livestock. (avoid flies and bad smell)