Portal frame arrives

Late afternoon yesterday saw the arrival of the prefabricated portal frames along with the brackets and bits to put them together. These are more than a week overdue and their late arrival has meant a temporary stop on site for a few days as nothing further could be done without them beyond the ground floor panels which are now in place .
However, things moved along again today as our main builder/project manager and two joiners started to the erect this steel framework into the gound floor panels. By the end of the day two of the three frames were in place and secured.
So why a portal frame? Well, this 1.5 storey house is very open plan internally with generous internal room heights (2.7m ground floor, 3.5m kitchen/diner, 2.9m first floor) such that the upper floor ceilings follow the roof line almost to the ridge, with a small loft space around 1.5m high. With this internal design it was tricky to use a (more conventional) truss system, so the portal frame is used to provide torsional stiffness to the building and carry a roof ridge beam, against which rafters will be supported for the roof. In effect, this is a contemporary take on a traditional method of roof construction.
In designing the roof we have also avoided the use of roof purlins (horizontal rafter supports) by using timber 'I-beams', each of which will span around 5m from eaves to ridge at a 45 deg. pitch and carry the weight of the slate roof supported only at either end. This not only keeps the internal structure clean and uncluttered, but their 352mm depth will be fully filled with insulation and their thin shear web minimises thermal bridging. The end result is a stiff, clean, super-insulated roof structure.
The down side to this constrcution has been additional labour/time and ultimately cost, but the end result should be worthwhile.

Daily Changes

The two joiners erected much of the ground floor on Monday and Tuesday which has been really exciting. Its terrific to see the rooms take shape and we are really pleased with the size of the window openings, particularly as we spent a long time last winter working through that element of the design. The joiners can't progress further until the steel arrives, this is delayed but due next Wednesday. In the meantime the scaffolders have been taking delivery of their kit and today have erected scaffolding on the west and south elevations. This photo is taken through the caravan window.

By and large we've had good weather since the start of the build, it is very mild at present which makes life comfortable for early mornings in the caravan.....however the past 2 days weather have included a large amount of rain and the area at the back of the house is somewhat muddy. Thankfully the caravans are on a concreted area.

Final photos today - 2 days collection of eggs and a piccie of Dora; generally the hens are laying 4 eggs per day which is quite good I think for ex battery hens and for the time of year. We've no idea if some hens are not laying at all but those that are have been using the nesting boxes. At this time of year with the daily reduction in light levels we can expect them to lay fewer eggs but at the moment our hens seem quite consistent.

Exciting Progress On Site

One of the landmark days on site - the joiners arrived at 7.50am, the first lorry and trailer load of timber frame a few minutes later. The first photo was taken around 9am as the timber was being moved to the house; the joiners spent much of the morning undertaking check measurements etc (apparently it was all within 5mm so that was good!) and moving the timber to the right place.

We had some wild Autumn weather at the weekend so it was a chilly post-frontal breeze as well as getting muddier around the site.

Around lunchtime the first wall was put in place on the wall plate - this being the northwest corner of the house where the guest bedroom is situated. As I was chatting on the phone the rest of that end of the house was put it in place - the wonder and speed of timber frame construction. This second photo was taken around 3.30pm and the house is really taking shape. This view is from the northeast looking at the kitchen on the left, the front door location in the centre of this elevation and then the ground floor bathroom at the right.

Final photo is the view from the window of the guest bedroom. You can see the rain coming over the hills!

True low carbon or eco-chic?

Probably since the oil crisis of the early 70's there has never been such a high level of public awareness and engagement in all things 'environmental', not least in greening up homes. In particular the UK Government has made a commitment for all new homes to be 'zero carbon' by 2016, an ambitous target which would make UK building regs on energy efficiency some of the toughest in the world, even exceeding the current high standards which exist in Canada, Scandinavia and Germany.

The problem is that new homes accont for just 1% of the housing stock annually at the current UK build rate, so what can the majority of the population do to reduce consumption and 'do their bit'? There is a huge amount of information out there and a good starting point is The Energy Savings Trust www.est.org.uk, but it can be a minefield as to what actions/technologies will truly bring genuine savings in energy, carbon and money. Here's a few ideas:

1. Insulation and draft-proofing/airtightness - do this before anything else, especially on the detailed design of a new build or extension. Usually, money spent on this has a much quicker payback than any of the technologies described below. For example, £2k spent on a mini wind turbine buys a huge amount of insulation and will payback much quicker.

2. Rainwater harvesting (for toilet flushing, laundry etc) - unless gravity fed or pump free, this probably isn't worth the cost or effort and will increase your energy consumption. Whilst saving mains supplied potable water which has used energy in its processing and delivery, it is unlikely that the energy used to do that by your water supplier will be less per cubic metre than by using a water harvesting system. Furthermore, if you are on a water meter the energy costs in operating such a system may not even be offset by the saving in water costs.

3. Mini wind turbines (fixed to house) - in most cases probably not worth the bother, but in some cases (rural, wind-swept property with no nearby obstructions) might produce useful power.

4. Mini wind turbines (standalone for farms etc) - worthwhile on windswept, unobstructed sites.

5. Solar panels (hot water) - useful and can provide up to 60% of annual hot water needs. Payback can be less than 10 years, but don't overpay for system (should be ca. £2,500).

6. Solar panels (PV, electricity generating) - expensive and long payback, but very reliable (we have them) and beautifully simple. Most cost effective on building integrated applications. A better choice than roof mounted wind turbines for electricity generation in most cases.

7. Heat pumps - good choice for well insulated rural new builds with underfloor heating not connected to mains gas. Be careful over promises of '75% savings' - they still need electricity to drive the pump!

8. Wood burning stoves - go for it! In the vast field of alternative energy, the joy of watching carbon-neutral fuel being consumed by fire within the highly efficient combustion chamber of a modern wood burner is rivaled only by the gentle rotation of 150ft wind turbine blades! If you use an open fire, three quarters of the energy in the fuel you feed it goes up the chimney; in a woodburner, three quarters stays in the room, not to mention considerably reduced emissions.