Your new home construction checklist

To help you maintain control over your house construction – and be another set of eyes for mistakes – buildingguide.co.nz has put together a comprehensive construction checklist.

Some of this you can do, some of this your designer or builder can check off on your behalf.

Building a new home is a big undertaking - find out how to choose the right builder for your project and learn more about the cost of building in New Zealand.

1. General building checks

• Materials and products match what was specified.
• Timber is at specified moisture levels on installation.
• Timber has the correct preservative treatment for its location.
• The house is set out correctly on the site.
• Plans and specifications are followed.
• Materials are installed to manufacturers’ instructions so you get the warranty.
• Finished construction is protected from the weather.

2. Early stages construction

Earthmoving and excavation

• Is the hole for excavation staked out correctly?
• Are the walls vertical and even?
• Has it gone to the correct depth?
• Are all cut earth faces supported and “cut in”?
• Where can this affect neighbouring properties?

Retaining walls

• Retaining walls must be included in the building consent and signed off.
• Is the ground supported during construction?
• Ensure the wall is drained behind and waterproofed/tanked if necessary.

Footings and foundations

• Footings need to be straight and correctly positioned, though the finish doesn’t have to be smooth.

Drainage and underground plumbing

• Are the pipes in the correct position, i.e. not where you may want to put paths or gardens?
• Are the drain holes or pipe vents in locations that will interfere with future use of the grounds, e.g. where you may want to put paths or entertaining areas?
• Are the vents in the right position?
• Will the drains carry sufficient water?
• Does your drainage system meet the Building Code?

Concrete slabs

• The concrete is laid on top of several things put in beforehand.
• There is a layer of compacted base course, a polythene vapour barrier, plumbing pipes and pipes taking electrical and other cable, in-floor heating and polystyrene insulation if required.
• There are additives that can be applied to the concrete to reduce cracking during or following curing; the concrete can be coloured, polished and/or ground.
• Ensure the floor is fully laid in one pour and there is no lag between deliveries.
• Ensure the concrete is cured properly under advice from your builder.

Scaffolding

• Is your builder using scaffolding or approved safety measures for working from heights. If not, they can be fined up to $500,000 and imprisoned for two years.
• Is the scaffolding secure?
• Are there safety barriers?

3. Flooring and framing

Wooden flooring

• Are the floor joists even and solid?
• Has the flooring timber been evenly laid?
• Has the timber been sufficiently seasoned?
• Are the plywood/chipboard panels secured properly and are they even – is there any movement or squeaks?
• Underfloor foil insulation is the minimum level of insulation you require under the Building Act but never shy away from increasing your level of insulation.

Framing

• Are the nogs (the cross-bars in the framing) level with each other?
• Are the studs (the upright timber) as spaced correctly at 600mm?
• If using timber framing, is the timber sufficiently dry and of the correct preservative treatment?
• Are the doors and windows correctly positioned and of correct sizes? Are the bracing elements in place?

Brick and block laying

• Have they been laid even and straight?
• Is there a satisfactory level of quality finish with no evidence of mortar splashes?
• Are the ventilation gaps free of excess mortar?

 

 

4. Plumbing

Plumbing

• Will you have adequate water pressure? Discuss with your plumber, designer and bathroomware supplier together if you can – water pressure can be a major source of confusion on installation.
• Have you worked with your plumber to ensure the pipes will be quiet?
• Is the bathroom plumbing correctly positioned?
• Do you have sufficient outdoor taps for hoses wherever you may need them?
• Are the gas pipes all installed in the correct position?
• Check the correct filters are in place for pipe size and water pressure.
• Is the hot-water source close enough to the kitchen/bathroom taps to minimise time lag?
• Are the nogs (the cross-bars in the framing) level with each other?
• Are the studs (the upright timber) as spaced correctly at 600mm?
• If using timber framing, is the timber sufficiently dry and of the correct preservative treatment?
• Are the doors and windows correctly positioned and of correct sizes? Are the bracing elements in place?

5. Roofing

Roofing

• All roofing must be laid straight and true and fixed correctly.
• Fixings (screws) must be evenly and neatly set out.
• All flashings, barge boards and ridge cappings must be in place.
• Do you have a guarantee with the roof?
• Have you supplied the roof shout?

Framing

• Are the nogs (the cross-bars in the framing) level with each other?
• Are the studs (the upright timber) as spaced correctly at 600mm?
• If using timber framing, is the timber sufficiently dry and of the correct preservative treatment?
• Are the doors and windows correctly positioned and of correct sizes? Are the bracing elements in place?

6. Exterior Envelope

Exterior cladding

• Is your cladding installer an LBP or being supervised by one?
• Is the cladding handled and installed as per manufacturer’s instructions with no damaged panels used? (Important - if not, warranties may be void)
• Are the flashings done correctly and properly waterproofed?
• Are the joins in panels even and level and regular?
• If using flat panels, is there sufficient weatherproofing?
• Are battens used to aid in drainage for water that gets behind the cladding?
• Is the cladding finished properly so the job looks neat?

Weather-tightness

• Avoid decks enclosed by solid walls with a lack of drainage and perhaps a handrail attached to the top of the top of the wall – water cannot drain and the weather proofing skin may have been pierced by the handrails.
• Avoid wall cladding materials finished hard down onto a deck surface or paving or paths: the cladding will absorb water from the surface it is finished onto.
• Avoid wall cladding that extends below ground level or landscaping materials, including mulch, built up against the wall – materials that are continuously damp will quickly deteriorate.
• Avoid decks that are constructed to the same height as the internal floor, with no fall for drainage, compounded by an outlet that can get blocked.
• Ensure suspended timber floors have space below the floor for ventilation to remove moisture evaporating from the ground.
• Avoid using silicon sealant rather than properly designed flashings. Ensure head and sill flashings are installed over windows and joinery.
• Ensure parapet walls have cap flashings.
• Kick-outs or diverters to apron flashings where roofs abut a wall surface ensure that water flows into the gutter and not down inside walls.
• Ensure monolithic claddings and tiled finishes have movement- control joints that allow building movement to occur without cracking the materials.
• Ensure adequate detailing on junctions between materials.
• Check the difference in levels between the surface outside and floor inside and/or that there is good drainage – without these the building may well fail to meet the performance requirements of the Building Code.

Window joinery

• Are the windows and sliders the correct size and design on delivery?
• Have they been fitted with sufficient waterproofing?
• Check correct and effective flashing has been installed.

Gutters and downpipes

• Do the gutters have the correct fall to ensure no pooling of water?
• Are the gutters installed correctly with overflow relief in case of blockage so heavy rain does not flow into wall cavities?
• Have you chosen a colour that complements the roof and external colour of the house, and has that colour actually been installed?
• Are the correct downpipes installed – colour, materials, profile (shape)?
• Are the downpipes in the correct location so they don’t interfere with external gates or the lines of your home?

 

 

7. Behind the wall

Insulation

• Have you got the correct R (heat retention) levels or better?
• Has it been correctly installed as per manufacturers’ specifications?
• Ensure there are no gaps - including corners in the joinery – these can reduce efficiency by as much as 40%.
• Discuss reducing thermal bridging in window framing with designer and builder.

Wiring and lighting

• Do you have enough power points and in the right positions?
• Are the power points and light switches installed evenly on the wall?
• Are the transformers correct for the types of lights you have installed?
• Are the lights selected correct for the specific job you want them for?
• Are the light fittings in the correct position for the tasks you wish to undertake or the ambience you want?
• Has the electrician created holes for the lights in the correct position?
• During installation, has the electrician installed the correct lights in the right places in the right way?

Phone and broadband wiring

• For new homes or major renovations are you installing structured cabling in a ‘star’ configuration, with each outlet wired back to a home distributor box?
• Do you have phone/broadband outlets in all areas? A double RJ45 outlet is recommended for bedrooms and other normally occupied rooms, with multiple outlets in the lounge, rumpus room and study.
• Are you using Cat5e cable or better?
• Is the computer cabling run separately to the electrical wiring?
• Ultrafast Broadband is rolling out around the country - have you taken advantage of supply in your area, and do you have the right technical setup at home?

8. Interiors

Interior Lining

• Have you checked with alternative wallboard suppliers to ensure you have the best product and best price for your project? (You don't necessarily need to use the default product specified)
• Is the wallboard handled and installed as per manufacturer’s instructions with no damaged panels used?
• Ensure framing is dry and straight. The use of thicker 13mm plasterboard with metal ceiling battens helps provide a straighter ceiling.
• Wall sheets should be fixed horizontally, as horizontal joints are less visible.
• To reduce the visibility of any imperfections use light colours and flat paints or textured wallpaper and avoid lighting that strikes a wall at a shallow angle.
• Use light shades or recessed downlights and position windows away from the edges of walls and ceilings or use shades.
• Plastering of the joins is critical, especially in ceilings in open-plan living areas – a single large ceiling is almost impossible to get completely flat but a poor job will be obvious and bug you for years.
• Do you have the correct panels for specific rooms; e.g. waterproof in the bathroom, fire-rated in the kitchen, sound- proof in the bedrooms?
• Are they even and undamaged?
• Ask what level of finish is being done? 

Interior and exterior painting

• Ensure correct paints are used in areas like kitchens and bathrooms, doors and window frames.
• Look for sloppy work and make sure it is cleaned up. Ensure angles are cut in to keep lines sharp.
• Is the preparatory work of a sufficient standard – filling holes, touching up plaster sanding, use of correct undercoats?
• Are the paints being used the brands you specified or cheaper alternatives?
• Have the painters got the correct colours as specified?

9. Kitchens

• Is the benchtop the correct size? If not, negotiate with your kitchen manufacturer to replace or discount.
• Are cupboards installed above the bench fitted properly to the ceiling and/or walls?
• Are power points installed at correct locations and with fittings that minimise intrusion onto bench space or tight spaces?
• Ensure workmanship on joinery is an acceptable standard, with well-fitted joins and hardware.

 

 

10. Bathroom

• Don’t forget ventilation and heating, especially underfloor heating. The room must be able to be fully dry within 30 minutes.
• Check that sufficient waterproofing is done.
• Ensure all glass is of correct NZ standard.
• Check tiles for chipping after laying and after other major items installed so damaged tiles can be replaced.

11. Heating and Air-Conditioning

• Do you have sufficient heating units for your new home?
• Have they been correctly installed as per manufacturers’ specifications?
• Is the gas flued to reduce moisture build-up inside?
• Have you considered the trade-off between purchase price and running cost?

 

 

12. Outdoor

Fencing

• Have you discussed the fence with your neighbour?
• Has the correct grade of timber been used?
• Are the vertical posts installed solidly and evenly?
• Is the fence the correct height or do you need to get building consent?

Decks

• If solid deck attached at the wall, is the drainage sufficient?
• Check where decks attach to walls to ensure the proper procedures are followed and weathertightness is achieved.
• Have attachments to walls been done properly?
• Is the deck rated to hold sufficient people?

Rubbish removal

• There will be rubbish left behind by the tradespeople and sub-contractors. Specialist companies can dispose of this in an environmentally sound manner.

 

This article first appeared in the New Zealand Building Guide. Read more about building your dream home at buildingguide.co.nz.