The 'ins' and 'outs' of buying a building plot!
Posted 23 May 2013 - 06:11 AM
We're not (and cannot) change the design significantly so all our changes are to do with putting in velux windows, increasing the size of the windows and door openings on the rear elevation, adding a window on the rear elevation (precedent set by house on adjacent plot) etc.
Our rationale to go to this architect for the design amendments for the house is to do with his knowledge of the site, the planning history and relationship with the planners.
I think he had released Autocad dxf files to one of the plot owners without any charge so this may be an option available to us too.
If we had detailed planning drawings in paper format, is it possible to get an architectural technician to draw up BR drawings and manage the liaison with SE and building control? Would this individual also be able to manage the tendering side of things?
We are quite keen on SIPS as a construction medhod despite a general body of opinion that seems to favour traditional breeze block & brick so jsharris's point about getting this SIPS supplier to take over structural elements, BR etc probably might work better for us.
Posted 23 May 2013 - 06:32 AM
Posted 27 May 2013 - 11:01 AM
I operate a business dealing with numerous German suppliers and I was inclined to evaluate pre-fab German made houses mainly on account of understanding the German work ethic and quality inherent in their factory productiion systems. HanseHaus is something I am looking at in detail.
Mantle Panel looks very similar in some ways. Are you going with their system? Have you had any issues with the mortgage side of things with this unusual system?
Any other SIPS system that you thought was better than the rest. I'd be grateful if you could PM me with these.
Posted 27 May 2013 - 11:24 AM
I did look at the Mantle panel system, but when I enquired they weren't able to offer particularly good insulation levels, they were about the same as most of the run-of-the-mill SIPs suppliers, at around 0.18 to 0.19 W/m².K IIRC, which was a fair bit poorer than we were looking for. We've gone for the Viking House panel system in the end (http://viking-house.ie/), as they seemed to offer the best performance/cost balance (typical wall and roof U values of around 0.1W/m².K and costs for an erected house shell, including foundations, but excluding roofing, windows, internal finish etc, of around £377/m²).
Malcolm Donahue on here (http://www.greencomfort.co.uk) was offering the best conventional SIPs panels I've seen, with U values of around 0.1W/m².K I believe.
The only problem I've had with the mortgage side of things relates to some lenders who still won't consider timber frame construction, either by restricting LTV ratios for them, or by not lending on them. I was advised that there were only a few lenders who still had this policy, and many had no problems with timber frame/SIPs type construction at all.
Posted 28 May 2013 - 07:44 PM
I have spent the entire bank holiday weekend looking at several SIPS options and quite frankly my mind is mush. So here are some potentially stupid questions-
How does one reach a decision on which of the numerous SIPS systems to best suited? I am a complete novice and don't even know what questions to ask and how to evaluate the answers.
Since most of these SIPS companies are relative new, what projections are offered on the life of the SIPS panels?
Where is the guarantee that a company providing a SIPS panel today will be around for the length of the guarantees
The general body of information out there seems to indicate that it is possible to get block and brick building to perform close to SIPS or timber framed building with care and attention. While SIPS costs more than traditional building is it possible to put the additional spend on greater levels of insulation in traditional build and get SIPS performance?
Any information will be very gratefully received.
As an aside, I have a brief chat with Hanse Haus (German prefab) to get an idea of costing and was advised of a cost of approx £1350 /m2 excluding foundations and kitchen/utility. I was advised to take this figure and add an extra 20% to get the build cost. Not all that expensive after all.
Posted 28 May 2013 - 09:12 PM
We started from the position of wanting a home for life. I took early retirement and so we wanted a house that we'd never need to sell. My personal priorities were for a house that needed as little energy as possible to run (more from an environmental perspective than a cost saving one), that had the lowest level of embodied energy in its materials (but without going uber green) and that fitted within the restraints of our (somewhat challenging) plot. My wife had clear ideas on what she wanted in terms of internal spaces and the garden. Inevitably there were some clashes; I was adamant we'd have to have an airtight house with very good heat recovery ventilation, she was convinced that opening windows was the only way to get "fresh" air, for example.
When it came down to choosing a build method and construction system, my first choice was SIPs. The reasons were straightforward (I thought at the time). We wanted good airtightness by design, and SIPs systems are inherently good in this respect. We wanted insulation levels that were around passive house standards, and I (wrongly, as it turned out) assumed that we could easily get this with SIPs. We were also planning this build all through last summer, so were a bit focussed on getting to a weathertight shell quickly, given the difficulties in building in very wet weather.
We went to several SIPs companies for quotes, and found a fair variation in price, but an even bigger variation in thermal performance. Overall, I have to say that I was a bit disheartened by the lack of enthusiasm from some companies in meeting our insulation requirements. It seems that the many companies "just" meet, or slightly exceed, building regs insulation and some really weren't interested in offering us something a lot better.
Part of my original thinking was to stick with local, or at least UK, suppliers, as I felt that it would be far simpler to be able to (relatively) quickly go and meet the supplier face to face. After talking to a fair few potential suppliers, and having driven around to see some of their projects, it's fair to say that we were a bit demoralised. I had the distinct feeling that very few suppliers really cared about building energy efficient homes. Some claimed to, but when you went to look at what they were building it was clear that they didn't really have much of a clue about the critical detailing needed to get a really good house.
The final deciding factor for us was the cost. We ended up with higher than expected site related costs (getting the site ready for the build and getting services in has come to around £60k). This then dictated that we look at cheaper ways of getting the performance we wanted. I did consider conventional timber frame, but past experience (from a previous timber frame house) has taught me that it can be difficult to get good airtightness with "stick built" timber frame.
We did briefly consider block and brick, but cost was again the killer. The planners were insistent that if we went for this they wanted the outer skin in locally quarried Chilmark stone, which would have been far too costly. An added factor was that, once again, I didn't get any sense from the local builders I spoke to that they understood the importance of airtightness and insulation detailing.
After much deep thought, and, it has to be said, not a little bit of concern, we started looking at non-UK suppliers. I looked at a few Scandinavian companies, but many produced semi-standard designs that wouldn't adapt well to our site, given that we had some fairly stringent planning restrictions on appearance (the old mill opposite is grade II listed). Eventually we settled on Viking House, in Ireland. I was still a bit uncertain, so we decided to go over to Dublin and see them. After a hectic day spent looking at houses they'd built, talking to them and visiting their factory down in Tipperary we were pretty convinced they could build exactly what we wanted, within our budget. The deciding factor was really the massive amount of enthusiasm they had for building very low energy homes. No bullshit, no eco-greenwash, just hard facts, common sense and a passion for building affordable low energy houses.
In terms of cost, our basic house shell and foundations, excluding the windows, roof and cladding, but including the under floor heating pipes, will be around £377/m². The roofing, triple glazed windows and doors, and external larch cladding pushes this to about £610/m². The internal fit out and finishing, plus the big solar panel array and the heat pump gets us up to about £1000/m². This is for a house that meets passive house levels of airtightness and insulation, so more than twice as energy efficient as a house built to just meet the building regulations.
Our final costs will be around £1450/m², but nearly a third of that is site related cost, driven by the massive retaining walls we've had to put in, the soil we've had to remove and the fact that we're off grid for water and drainage (so have to have a borehole and package treatment plant).
Our solution may well not suit you, but hopefully the above (somewhat lengthy!) tale may help you work through the pros and cons against your own specific priorities and needs.
Edited by jsharris, 28 May 2013 - 09:15 PM.
Posted 12 June 2013 - 04:44 PM
In the meanwhile some issues have cropped up causing concern.
The plot next door has a basement build and their cowboy builder disturbed the soil on the plot we would be building on. Some remedial work will be required to sort this out and the seller has agreed to bear the cost of this by way of a retainer on the purchase price of the plot. I have made some enquiries and been advised that standard footings for the size of the house would cost about £8-10k while piled foundations could cost around £25k possibly more. The exact figure cant be determined without spending a fair chunk of money. We havent decided the route we want to go down (block/brick, timber, SIPS etc) so no structural drawings are available, soil sampling to determine the exact area and type of problem will have to be carried out and all this in conjunction with a structural engineer/BR will determine the route forward. I dont want to spend this money without knowing that I have secured the plot for sure and its a risk exchanging contracts on the plot without knowing exactly what these costs are.
The plots (4 in all) are marked on architects drawings but there are no markings on the site itself. The seller is a little but too relaxed for my liking about this and given that houses on both sides of the plot are built now, one cant rule out both plot owners having pinched a few cm of land in the process. Potentially this makes the plot smaller than the one I am paying for and worse it makes the house unbuildable on the plot or not how we'd like it to be on account of a narrower plot . It potentially also brings in issues with regards to party wall agreements with house owners on both sides further adding to building costs and complexity.
I am at a bit of a dead end on how to best resolve this so any suggestions are welcome.
Failing that, we might just walk away before too much more cost is spent on this building plot and look elsewhere.
Edited by joiner, 12 June 2013 - 05:47 PM.
Posted 12 June 2013 - 07:09 PM
Getting a soil engineer to give you a report on the likely foundation type needed would reduce this risk, too. Again, this isn't something that's particularly unusual, a lot of plots will need this to reduce the risk of running in to higher than expected foundation costs. An alternative to this is to look at using a foundation system that will work on pretty much any sort of underlying ground. This is the approach we've taken, as even with a soil report there is a fair bit of uncertainty as to the true conditions. The option we're using is the Viking House Passive Slab, which will work on pretty much any type of ground and isn't expensive, given it's performance (our 84m² footprint slab will cost around £4200, including the engineers sign off for BC).
Posted 12 June 2013 - 08:39 PM
And more related, what's the cost comparison between DEEP strip foundations (say 5 feet deep) compared to micro piles and a ring beam?
Edited by joiner, 13 June 2013 - 06:56 PM.
Posted 13 June 2013 - 12:33 PM
All valid points that you make. Its just making me wonder if I was been a bit too relaxed with this buying process.
I am paying top whack for this plot and the more of these extra and unforeseen expenses I am seeing, the more it makes me wonder if it should be paying less for the plot (I naively assumed that since this was a structured sale with 4 plots, it would be much more straightforward than the 'norm').
Clearly I need to go back to the drawing board and rethink this. I am looking to spend around £250-300k for a building plot (which is what I consider to be a handsome amount) in the Bucks-Oxon borders. I am sure more and better opportunities will present themselves in due course.
Posted 13 June 2013 - 05:39 PM
Just get a 60m tape and measure it. My plot had lost a meter somewhere. The house one side is 16th century and the church the other side even older so it must have happened when the maps were drawn up decades ago.