You're a brick, you really are...

Had confirmation today that Tim @ RRA has negotiated a change of cladding material for the ground floor of the house.

The original plan was to clad in local stone, but this proved to be VERY expensive thing to do and anyway it wasn't my first choice.

The stone cladding would have looked something like this:

The brick version (with railings instead of solid walls), would look something like:

Getting (And Staying) All Heated Up

Although we've had previous discussions with the Architects about how to the heat the house we now have to make a decision, and its not an easy one to make.

Few people are experienced enough with building Passive houses to know that a particular design will work perfectly. There are computer simulations which help you decide if your design should work, but there is still no absolute guarantee of success.

A Passiv house has to be built in an extremely high standard to work: it needs to be @ 20 times more air tight than is required with the current building regulations. We have a head start in that we are using ICF which by definition builds a sealed set of walls.

You then need to have top class seals between the walls and windows and then the walls and the roof (difficult to do apparently).

Then your windows need to be triple glazed with a uValue of @ 0.7 - which requires specialist windows.

If you get that right then you need to build in MVHR - Mechanical Ventilation and Heat Recovery. This system means that house is properly ventilated with fresh air but as the clean is drawn in from outside it is heated by the air already in house.

You then remove all standard ventilation from the house: all extractor fans and trickle vents go.

With that in place, plus the right insulation in the walls and roof, you are minimising heat loss.

Then you need to think of what is going to actually get heat into the house in the first place. There are three categories to consider:

1. Solar gain
2. Humans - we give out @ 80W or @ 240 BTU/hour
3. A heating system

If you gain as much solar energy in your house as possible plus any energy gained from you being in the house, then it is possible to not have to add in any additional heat. To build a house on this basis is obviously a gamble.

I think we are likely to add in one or more of these additional items:

1. A wood burner (with a back boiler to give us a backup source of hot water)
2. Underfloor heating
3. Electrical heating to boost the air temperature coming out of the MVHR unit (hopefully we would be using electricity we are generating)

The bottom line is that we want to be as off grid and self sufficient as possible but we also don't want to end up with a house which doesn't keep all inhabitants warm.

Kick off!

I'm just back from the kick off meeting for the next phase of the project and although the bills are scary, we suddenly feel a lot closer to actually getting something built. We've even put the wheels in motion to put our current house on the marker as I will need the capital out of this house to build the new one. That kind of thing REALLY makes it feel real, after so long of wondering if it would ever happen.

RRA Architects have managed to get alot of the Buildings Regs drawings done ahead of schedule which pulls the build start date into 2011: the build is currently down to start mid October. We had imagined that we would be into 2012 before anything happened on the ground.

The sums involved are very frightening though. We started off with a budget of 250-300k, however this soon looked unrealistic. When I got the initial cost estimate from the Quantity Surveyor this week I had to lie down: the initial project cost estimate was for 462k (with professional fees on top of that)! There is plenty we can pare back and some items in the costing that we do not need, so we have agreed to go with a budget of 400k. That will stretch me a little more than I would like but it's affordable. That 400k includes an 8% contingency so, you never know, we might just make under that...

We can now start thinking about kitchens, bathrooms, floor coverings and the like. This is my kind of fun, but with the two of us there is some serious negotiation to do!

How we heat of the house is also still be decided: there are plenty of options but the key will be finding the most cost effective solution and also a solution that we are confident about being able to deliver the warmth and flexibility. More on this in another post.

Planning Permision Granted

Well, it's finally happened: we have our bit of paper which says we can build the house. It's been a bit of a roller-coaster, for us novices at least, but we didn't have to go to appeal etc which is a relief.

There is a long list of conditions: we have to get approval for pretty much every material we use, but as the plot is within an AONB (Area of Outstanding Natural Beauty) this is pretty much what we expected.

The Quantity Surveyor is currently working a basic costing plan. This is the first attempt to put a realistic cost together and we have been warned the the results might give us a nasty shock....

There are various charts you can use to estimate a build cost but there are various additional consideration for this plot and build. Firstly there is alot of excavation to do. The house will be fit in snuggly against the hillside and to do that we to chop out a bit of the hill, plus we have to level the car parking area. The spoil will then need to be taken off site and disposed of. There will also be some reinforcing work to ensure that ground behind the house stays where it is when we do the excavation.

We are also costing in things like use of Welsh slate, local stone to clad half the house and self cleaning render for the upper half, not to mention triple glazing to suit the Passiv house type design. These are all expensive items. I really hope we don't have to compromise on too much. The thought of having to use Chinese slate to cut costs doesn't sit very well with us - especially as the Welsh hills are within view of the house.

We have a meeting with the Architect, Quantity Surveyor and Structural Engineer to go through the costings and plans next Friday. Exciting but scary times.