Ian

@recoveringacademic It looks like a fantastic place to live! Btw, Mark Brinkley's book "The House Builders Bible" is useful and a good read.

@jamiehamy Mark Brinkley's "Slope Law" - every 5 Deg of slope = +£5k in costs (although it's obviously not really that precise and can cost considerably more.) @JSHarris Part M of the Building Regs allows for exemptions to the standard wheelchair requirements if the site is steeply sloping.

Just a quick note to say that PD rights are not the same everywhere. They are reduced if your house is in an AONB or National Park.

@MikeSharp01 As a possible alternative there are liquid chemical (spray on) curing compounds that are available however I have no personal experience of those. That's an excellent result Mike! Mike - you mentioned that your concrete slab will not have an applied finish. I think the biggest single risk with the larger house slab that you will be doing next is cracking which would then be visible as the slab surface will not covered later by carpet or tiles. If an engineer has designed the slab for you then they should be able to advise on that. Have you got reinforcement mesh in the slab and does it have UFH?

@MikeSharp01 it depends on the time of year that you pour the slab. Here in the U.K. you would not normally wet a slab like that by misting with water unless it was a very hot summer. I've never seen that done here in the UK (maybe it's advice from the USA?) Here in the U.K. normally they are shaded from direct sun and rain and if it's summer the usual method to slow down evaporation of water from the concrete and aid proper curing is to cover it with a layer of polythene as soon as you are able to after the slab is poured.

@MrP the reason that you're not supposed to tile onto plaster skim or onto normal plasterboard in a shower is that gypsum plaster is hygroscopic. Over time as cracks develop in the tile joints and water gets through the plaster will swell & fall apart.

@MikeSharp01 it helps if you can get the slab covered by the roof and out of the rain as soon as possible after the concrete is poured. Often it's slabs that are exposed to a lot of wetting and drying which experience problems with efflorescence.

@MikeSharp01 I'd try brushing it off for a while and see how you get on. There's a good chance you won't need acid. It depends on how much time you have but if it's still happening when you are ready to apply floor finishes on top of the slab then it will need dealing with properly as adhesive etc won't stick to it.

Unlikely that it's anything to worry about. It looks a bit unsightly but it looks from the photo as if it is simply some efflorescence coming to the surface of the concrete as it dries. explanation link: http://www.concreteconstruction.net/how-to/efflorescence-causes-and-solutions_o Ian

@Onoff Dodgy place the internet when it comes to advice!...I couldnt work out if that video was supposed to be an official one from Aquapanel but it's definitely wrong regarding the screw depth. You'll see the correct method on Aquapanel's website. Quote: http://www.knauf.co.uk/technical-assistance/technical-faqs "The correct use of the correct type of fixings is vital to both the strength of the whole partition and to prevent future problems, such as cracking of the joints. Plasterboards should be fixed securely to all supports, using approved Drywall Screws, working from the centre of each board. Screws should be positioned not less than 10mm from the board edge, at 300mm centres - reducing to 200mm centres at external corners. Screw heads should be set in a ‘depression’, and the screw gun torque set so that neither the board paper or core are broken." I was involved recently with a high-rise project in london where we had to complete a job where the client was suing the contractor in a multi-million £ claim because they had over tightened the Aquapanel screws in dozens of bathrooms that were to be clad in marble. Part of our contract work was to replace all the Aquapanel. Because it was high-rise the building had to be able to cope with significant movement in high winds without anything falling off walls. At the top it moves about 400mm.

For the tile backer panel to have bowed like that there must be a problem with the fixings - either they have pulled through the board or they are missing altogether. Different tile backer boards have differing fixing requirements e.g. Wedi's system involves washers to spread the load. Knauf Aquapanel needs special screws applied using torque control as they aren't supposed to break the surface skin of the board - If you break the board paper or core with the screw head it invalidates any warranty.

@Gimp our planning application had some unusual aspects to it that meant that even though I work as an architect I knew before we started that we would need expert help so I employed a local (N Wales based) firm of Planning Consultants. Without their professional help and expert advice we wouldn't have had a hope of getting the PP that we eventually achieved. I can thoroughly recommend them - their fees were very reasonable and they were efficient and clear with their advice. Their appeal success rate is much better than the national average. Let me know if want me to whisper their name to you or I can give it publicly if that's allowed in forum rules. I've no connection with them other than with this one project which was a holiday home for myself on a plot of land that's been in the family for 90 years. Edit- admin have said it's okay to mention the name of the Planning Consultants in North Wales that I used - its a company called Owen Devenport http://www.owendevenport.co.uk/ and I dealt with Berwyn Owen and Jamie Bradshaw. (context - although I work as an architect I have no professional or personal connection with Owen Devenport other than employing them to work for me on this one project - a process which lasted 3 years . I can recommend them without reservation. We wouldn't have got PP without them)

Like @joe90 our PP which was in an AONB in N Wales took 3 years including 2 full planning applications and an appeal - the local planners were obstructive and slow and fought us every step of the way. Thank god for the appeal process which was efficiently dealt with and relatively quick - the inspector sent up from Cardiff was brilliant.

Sounds brilliant! It took me, wife and No1 daughter 4 full weekends to paint our really small 71m2 bungalow the old fashioned way. The worst part was doing the cathedral ceiling and the transition lines between wall & ceiling colours.

Lol! ? Good luck and let us know how you get on with the timber frame spec etc. Ian

Sorry to be blunt but there's no real way of sugar coating this - you urgently need to get some professional help with this build. Your questions demonstrate a basic lack of understanding of simple construction issues and it's some of the scariest stuff I've ever read on a self-build forum. What involvement have you had so far with your Building Inspector? Have they approved your foundations?

Good result! Nice one!

Thanks for the link - very interesting! The biggest surprise for was the price at £350k which I reckon makes the cost for gross external area at £2,800/m2. This compares to £1,050/m2 for something similar that I've just finished (based on mobile home design & size limits but we ended up getting PP to build it as a normal house with normal foundations.

We've recently completed a small holiday home in North Wales (71m2) and are using bulk LPG for similar reasons to you + with it being used mainly at weekends and very remote with no close neighbors I figured LPG was less vulnerable to theft compared to oil. As a bonus it's also nice to be able to have a gas hob for cooking. We connected our LPG tank to the combi boiler at the beginning of Nov last year and paid 30p per litre for 1200 liters. It's a 2 year contract and there's a fixed max uplift price for year 2 although we won't need this as the supply will last us longer than 2 years. Avanti and Calor both offered the same deal - free tank and connection and 30p/liter (we laid a small concrete slab and dug the trench for the pipe). This price works out at about 4.3p per kW. There are regulations with bulk LPG now which mean you can switch suppliers after the 2 year contract with little/no hassle. The regs govern what happens to the bulk tank at no cost to you assuming you're renting it. Our rental is £60/year. Most gas combi boilers have an LPG version so there's a good choice and great boiler efficiencies - ours is 91% efficient. Assuming that your house design has good insulation you may find that the difference in running costs between LPG and oil is less than you think.

great looking result!

What a relief eh!!? Did you manage to keep your builder or had he already given your slot to someone else?

I thought I'd play 'devil's advocate' and give you an alternative viewpoint. I've just completed a new build holiday home bungalow in N Wales of 71m2 (internal area). After looking closely at the economics of building something to Passivhaus standards of insulation I decided instead to keep things very simple and instead designed it to comply with minimum building regs standards. We exceeded the minimum building regs standards by a small margin and, as built, our predicted energy demand is 43 kWh/m2/yr compared to the Passivhaus standard of 15kWh/m2/yr. We're using bulk LPG (which is approx double the price per kWh compared to mains gas) yet the predicted annual cost to heat the house works out at £135/year compared to £45/yr if it were to Passivhaus standards. Our annual space heating demand is predicted at 3,012 kWh £90/year is not a lot of difference and it would be circa £45 if we had mains gas available. The building is very small to keep costs low and this size issue was a factor in the decision to go with minimum building regs compliance. For example it has meant that I was able to keep external wall thickness to just 270mm maximising the usable internal area of the building (140mm timber stick frame with external cedar weather boarding). Just a thought for you to consider. Ian

For simple jobs like a house lots of BC officers will let you agree the foundation depth with them on site once it's dug. The exceptions are usually when the ground bearing capacity in an area is known to be poor (e.g. peat) so a designed foundation solution will be required. Ring them and ask.

I don't think there's any marked benefit of one system over the other - obviously you would be handling half the quantity of boards using the Fireline. It would come down to which option was cheapest I guess? 15mm Fermacell may be your best bet as PeterW suggested due to its strength but I have no idea how the price compares with normal plasterboard. Ian

For the internal skin - you will get 30 minutes fire protection from a single layer of plasterboard or 1 hour by using 2 layers. The main alternative is a single layer of 15mm thick Gyproc Fireline board. Ian