House building and your thoughts

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#1112424 20-Aug-2014 21:23

You don't actually get more solar gain in the built environment in winter. For space heating the period of gain is really important.

You get more shading from other buildings as well as much shorter periods of solar gain. You can split hairs about the terminology but the heat loads are really clearly defined when you watch them.

mattwnz

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#1112495 20-Aug-2014 22:52

Handle9:

Solar doesn't come on and come off instantly, it does so slowly. It also doesn't have a hell of a lot of effect in the middle of winter when you actually need heating. In reality you can get nice comfort control out of underfloor heating, and has the added benefit of no draughts.

It does if it is designed properly. Infact you should only get solar gain in the winter, as overhangs should block any solar gain during the summer when you don't want it. I have designed and a built house with passive solar heating, and that is all the heating it has apart from a wood burner, which is rarely used. The difference though it has over a conventional house, is that it has concrete internal walls which also get heated by the sun, and regulate the temperature during the day and night, so you get a very constant temperature. In the cold evening it is great to walk into the building as it feels like the heaters are on, as it is constantly a nice comfortable temperature. The mistake many passive designed building make, is that they don't have enough thermal mass in them, so they get big temperature swings during the day and night. Thermal mass also helps in cooling the building during the summer.

Swanny

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#1112508 20-Aug-2014 23:31

maoriboy: Here's something I forgot to ask in my initial post. Single or multi storey? What are your thoughts on basements? Is it really cheaper to build up/down than out?

My wife wanted two story (and I like 'em too) but the costs just skyrocketed.

Even a single story house needs scaffolding and netting etc now so I guess that cost is no longer so much different.

mattwnz

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#1112511 20-Aug-2014 23:41

Swanny:
maoriboy: Here's something I forgot to ask in my initial post. Single or multi storey? What are your thoughts on basements? Is it really cheaper to build up/down than out?

My wife wanted two story (and I like 'em too) but the costs just skyrocketed.

Even a single story house needs scaffolding and netting etc now so I guess that cost is no longer so much different.

IMO the OSH requirements these days seem like overkill. Would be interested to hear what builders think of it, as it adds a lot to the price of building.

floydie

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#1114702 24-Aug-2014 18:41

mattwnz: With network cable, make sure it is installed in conduits. This allows you to either pull more wires through in the future(if it is wide enought), or upgrade the cabling.

sorry but as a sprky i simply dont agree with this. conduit is expensive and most single story houses simply dont require it. if its a two storey and you need to get between floors then i may consider it. you cane EASILY get network cable around a single storey house if you simply put draw tapes in the walls

Batman

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#1128720 15-Sep-2014 07:17

got something on stuff so i'm just gonna quote it all in case it disappears

Long before the labourers arrive on site, there is much research to be done including selecting the right site, choosing a design and finding a builder. Some aspects of the design, such as double glazing, are now legally required, but there are many other decisions to be made, right down to fittings, landscaping and the shape of your bath. Take your time, says Brendon Ward, acting chief executive of the Registered Master Builders Association. "I know a lot of people who've built and say 'gee', it was much better the second time around because we knew so much more." One of the key decisions will be whether to get an architecturally designed house or buy a "spec house" from a range of designs by a "volume" builder. "The benefit of a spec home is that they know all the measurements and you get your room sizes that match the number of gib panels they need to install," says Ward, "so there's not a lot of wastage."

FINDING A BUILDER Finding the right builder is often a matter of asking around or checking the Registered Master Builders website. Aside from actual building experience, a builder needs to have a number of other attributes including good time management and people skills. Ward says a good relationship between builder and client is crucial. "You need to have a rapport with your builder. You need to know that you will get on, not only when times are going well but when decisions have to be made or things aren't going quite as well as they could be." Ward likens the process to a job interview. "If you're looking to hire staff as an employer, you're going to interview those people and you're going to seek references and maybe take them out for a coffee ... and that shouldn't be any different with a builder. "You're effectively hiring a company to do something for you which is highly emotive and something that you're going to be living in for a pretty decent number of years ... so you need to go through that due diligence process."

CONTRACTS Ward knows of people who have built their homes "on a handshake" but by law from next year, every building project worth more than $30,000 will need a written contract. Registered master builders offer three types of standard contracts. One is a staged contract, which for a new build has about 20 stages where payments are due, and the second is a labour-only contract, based on hours actually completed. The third option is a progress payment contract, where you make payments on a fortnightly or monthly cycle. All contracts should outline what the payment cycle will be, the level of deposit, and what should happen when things go wrong. Association contracts request a 5 per cent deposit upfront and also make sure customers only pay for what has been received. That might be in time or supplies or goods, "but apart form that initial 5 per cent deposit you're not paying for things in advance," says Ward. When the build goes overtime, there should be room within the contract for a "retention," which means you withhold the final payment until you're ready to move into the house. A guarantee is also worth considering in case your building firm collapses or some other mishap occurs. Master builders offer four different types of guarantees, and each guarantee has four parts: the deposit, non-completion, a two- year workmanship period and a further eight-year structural defects period. "Non-completion" means that if the builder can't finish the work, the firm needs to remedy the situation or another member builder will step in. All up, it is a 10-year guarantee but customers can opt out of various parts of it. Some registered builders simply factor the guarantee cost into their contract, others offer it as a separate item. There is no trust fund for money paid in advance on houses, says Ward. "That's why we advocate only 5 per cent of the deposit and encourage people to take the guarantee for a deposit."

KEEPING TRACK Avoiding a budget blow-out means keeping track of expenses as they come up. Ward recommends using a spreadsheet but then, "I'm a spreadsheet kind of guy". Bridges says the stress of not knowing whether he was spending too much and what the final size of his mortgage would be was the downside of his experience. "Although we had a fixed price from our builder, which I think is important to get, there were so many things that were outside that contract that we were organising ourselves, that the total spend was always a bit of a mystery until the end. "I think that could have been solved with a little bit more planning and careful financial planning and time on our part ... Nobody tells you how to do that. If you're not naturally a good budgeter and controller of money then you'll struggle with that."

EXPECTATIONS A new home brings with it a host of expectations. According to Ward, you can expect as a client to have a house in line with your agreement and to the specifications you agreed. Any variations should be agreed in writing. You can also expect to be kept informed of progress along the way, and that if there's any dispute, that it can be resolved within the clauses of your contract. Ward says the federation has a dispute team which often can resolve things with a phone call but can do mediations. If you choose a builder who is not a federation member, the contract will be the key and the court may be your next step. Disputes need to be nipped in the bud, says Ward. "Our experience is that the longer that it takes to resolve, the harder it is to resolve, because of the emotions that get into it." Moving in Once the key's in the door, you would expect that a builder's job is done. But as a recent building industry survey showed, something almost always needs to be fixed up afterwards. Under the new laws, a builder must come back to remedy a problem within 12 months of completion. If it is an issue of workmanship, Ward says he would expect the builder to pay up, but if it's the quality of the materials, the supplier might be at fault. Bridges says he is not sure one ever really finishes a house. "We've got a list of about 75 small details that actually haven't been finished by our builder. from little things ... to quite major things like there's a breeze coming through the front door. "And we can't get them back. We owe them $25,000 but they're just so busy that it seems to be right, we'll just go on to the next major thing we have to do."

- Stuff

bfginger

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#1171239 8-Nov-2014 07:57

Windows may let the sun in but they are poor insulators and can make an otherwise well insulated house go cold when the sun isn't shining. Carefully choosing what joinery you have installed can make a huge difference to how warm the house is as the thermal performance of most window frames installed in NZ is very poor. Build quality can be poor too with most having deficient designs like how some uPVC products are unfit for our conditions. Thermal breaking is very important for metal joinery as a solid metal door is nothing but a giant heatsink.

Ask for low-e glass and know the R value of the windows you have installed. Better quality windows available in NZ can approach R0.9 for double glazing but just one third of that rating is usual. Pelmets and thermal curtains help insulate windows too.
http://www.level.org.nz/passive-design/glazing-and-glazing-units/measuring-glazing-performance-key-concepts/

As others have said, go above specification with the insulation. The building standard only requires R1.3 underfloor insulation so go far above that if that's relevant to your build. Wholesale prices for polyester are slightly more expensive than fibreglass but it's more durable.

Make sure the hot water pipes are lagged. The cylinder should have a spill tray under it and an insulation wrap unless you want waste heat for a drying cupboard.

Most internal garages aren't insulated as well as they could be. You can now buy insulated garage doorsAnd make sure there is insulation between the garage and the rest of the house. Garage carpeting can allow it to be used as an extra room.

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Trade NZ and US shares and funds with Sharesies (affiliate link).

Niel

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#1171281 8-Nov-2014 11:20

Definitely specify the internal garage needs to have external walls and ceiling insulation in addition to the standard insulation between the living space and the garage. Also double glaze (or triple if you can afford it) the garage, which is normally only single. It cost little extra as they are already there to do the job. For the garage door you can pay lots for an insulated door, but it will still leak around the sides (even the good stuff, it will leak after a short time). You can just as well go to Expol and order polystyrene cut to the exact dimensions needed for your specific garage door, and then put thin MDF/ply over the top to sandwich it in (this works well for metal sectional doors). Guy at work did it, and he is critical on thermal performance like getting the right triple glazed uPVC windows from Europe, etc.

I would actually put insulation in all internal walls, preferably noise insulation but thermal is actually almost as good for noise and cheaper (noise insulation is just thinner and denser/compressed to fit internal walls instead of external walls). Especially for bathroom "noises", but also to make bedrooms quieter (from living space noise).

Ethernet what you know you need, especially 1-2 at all TV points but fast switches are also cheap, and then just accept that you will use a fast wireless network for whatever else because it will never be in the right place anyway. Who cares if downloading a large file is slowed by wireless, it still takes only a few minutes without hogging the internet bandwidth on one PC and only a few years ago the same download would have taken 10h if it was successful on the first try.

You can never have enough Volvos!

benokobi

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#1173638 12-Nov-2014 15:36

Underfloor heating can be a pain. Grandparents built huge house and their power cannot handle the demand put on it leaving one end "cold" and one end 28 degrees. I guess it would be fine if the house was small.

bfginger

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#1181289 22-Nov-2014 15:10

Have wired networking installed over relying on just wifi. Wifi may work for web browsing but it isn't as fast and reliable as wired and you may have your bandwidth disappear whenever your neighbours start using their wifi.

If you don't want air from outside coming into your house through the garage door you should have an external door between the garage and the rest of the house. Many houses have an internal door there which means the wind blows around it and freezes the house in winter.

I wouldn't get a shower extractor fan with one of those 50w halogen lights in it. Electricity, water, heat and dust accumulation aren't a good mix. Many rangehoods and extractor fans act like open wind tunnels so see if you get a product that closes off when not in use. Make sure they vent them outside. There are now rangehoods with the fan mounted externally so they don't make much noise.

Most of the paints use toxic chemicals so investigate "eco" paints. There are several local companies producing ecopaints including one that does plant based oil enamels.

Triple glazing on an average window frame won't retain more heat than double glazing on a good window frame. Triple glazing won't let as much light through as double glazing so it may not be of much thermal benefit on the north side in warmer parts of the country. I like the idea of using motorised awnings to control summer sunlight instead of extended eves as extended eves will block out the sun on cold Novembers like this one.

If you really want the house to be modern and energy efficient you could build one of these

http://tvnz.co.nz/close-up/warm-home-without-electricity-video-5038807

But I do wonder how long air tightening from adhesive tape would last.

Niel

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#1181455 22-Nov-2014 22:24

Make sure the electrician does not remove the shutter flap from the bathroom extractor fan... Ours did and threw it away, so we get a draft. Typically it gets removed to improve efficiency. And yes, 2x extractors plus the kitchen extractor equals a very large hole for drafts.

Ask the electrician to use concealed wiring for the towel heaters. It is just different mounting feet, was included in the rails we bought, but our electrician threw it away and used the standard feet with exposed cable. (Do you see a pattern?)

You can never have enough Volvos!

Brat

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#1181496 23-Nov-2014 08:07

HUGE topic!

I went with a 'design and build' builder but actually they were more of a package place. Fixed price up front and pricing options at every change were good. They proved annoying in only one instance and the earthquake resolved that for me.
Chose one of their designs but local regulations required a change and so in the end designed my own and their internal architect drew it up.

SITE is key! Get a flat site and check orientation - both for north and for access (you don't want to waste space on a long driveway or put your garage where the best sun is).

Future proofing these days means wired ethernet. I have Coax to all major rooms as well for TV. I put each drop in two locations in each room (plus power points - you will need more than they generally offer) so that your other half can "rearrange" without impact. ;-) I saved money here by installing this myself since it's part of what I used to do for a job. As I play at home I put in a full rack system but that is overkill for almost everyone. Ethernet will also work well for phone points. Again, remember power points! If you don't want to put everything in at once (good plan) then drill large enough holes and install draw strings. (Conduit is not generally necessary in a house). It IS necessary outside though! Think about an outside power point and/or running power to any garden accessories you might have. I put in a solar-capable hot water cylinder but we don't use enough to make a solar panel cost-effective yet. This will happen eventually but by then we'll probably be a two person household and we'll downsize. We use heatpumps for heating but also have an efficient wall heater inset into the hall wall.

Whatever you do, see if you can get a 3d walkthrough or imagine living in the house as planned. The more time you spend on this will aid you in choosing lighting layouts (light switch location is important), and general house layout and "flow".

Our budget was bang on until we required extra foundation support. (site is key). Had to forego a few things...the only thing I regret not choosing is thermally broken windows - double glazing is good but in winter, I get condensation on the windows frames. We came in on budget still though because we had allowed a 10% overrun in our original plan. Oh - I put in a metre-wide insulation around the perimeter under the slab - the 80/20 rule that insulation there is best bang for buck.

Once signed up, check every few days or day if lots are happening. I detected the builder installed the dining room window in the wrong place that same day. These things happen. Esp check that insulation is properly fitted before the gib goes up...this part tends to be done in a rush at the end...had to get that resolved.

Only time package builder was an issue was in my choice of laminate floor - they would not use it. (or if we did, there would be no warranty on it). Earthquake (I'm in ChCh) was great for that - fish tank water stuffed up the laminate and so I replaced it with my original choice (Torlys which can have individual boards replaced).

So...would I build again. Yes. Would it still be stressful? Most likely - it's the project planning aspect almost all builders/architects are not good at.

Niel

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#1181739 23-Nov-2014 20:39

Brat: Torlys which can have individual boards replaced

We got Torlys to install our floor themselves (in Auckland), just excluded it from the builder's package. You do not need floor coverings for COC sign-off.

You can never have enough Volvos!

Brat

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#1181812 23-Nov-2014 23:22

There weren't any installers for Torlys in Christchurch at the time so that made life interesting. Didn't matter in the end as Earthquake resolved the problem for me and I only wanted Torlys to prevent replacing the entire floor which we had to do when the earthquakes ruined one part of it. ;-P

bfginger

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#1183604 26-Nov-2014 20:15

Thermally unbroken aluminium window frames can negate the benefits of double glazing as single glazed of anything else may perform better. The quality of the thermal break in thermally broken aluminium varies so the best has nearly double the R value of the worst.

Ideally joinery should have multi point locking. It is standard in Europe but that may be because of the relative fragility of most uPVC joinery.

Two storey houses that aren't climate controlled are often too hot upstairs in summer and too cold downstairs in winter. Doors at the bottom of the stairs may help prevent warm air from rising.

I put in a solar-capable hot water cylinder but we don't use enough to make a solar panel cost-effective yet.

The panels and other hardware should be relatively inexpensive. What is expensive are the margins being put on it in NZ by most importers and installers. Many of the imported flat plate solar collectors installed during the 2000s are now rusted because they were poor quality too. So you can see why solar thermal is so rare in NZ.

If your hot water cylinder has a dedicated cupboard it should be worthwhile having the walls around it insulated.

For walkthrough and design there is software you can buy or use for free like this one

http://www.sweethome3d.com/

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