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About this blog

Details of my Passivhaus self-build in Shropshire

Entries in this blog

 

Finishing the Shell

Sorry for the delay since the last blog. Things have been very hectic keeping a track of everything that is going on with the build and holding a job down !  As we approach end of January and move into February there are lots of things going on simultaneously on site including battening the roof in preparation for the roofers, finishing of fitting the smartply in preparation for blowing in the insulation and fitting the windows and doors.       The first window goes in on 30th January. Many of the side reveals to the windows have splays to help spread the light from the window.  We are using Green Building Store Progressions windows and Green Building Store Ultra doors. The Progression windows are expensive, but the narrow sight-lines give a lovely contemporary look and very little of the frame is visible outside, so it should be as maintenance free as you can get and seems like a good investment. The Ultra doors look very similar to the Progression doors and are of a similar thermal performance but are more cost effective to purchase.       From the 12th - 15th February, the Warmcell insulation is blown into the frame. I hadn't realised, but you can do this before all of the windows are fitted, as long as the boarding out is completed inside and out.    By 21st February all windows and doors are fitted. A lot of time has gone into ensuring the windows are fitted properly and are as airtight as possible. In parallel, the brick plinth is built. Whilst you won't see all of this once the ground levels are built up, I am really pleased with the quality of the job.      Next job is and fitting the Aquapanel in preparation for the rendering.       The roofer we had lined up pulled out at the last minute, but we are able to get a local firm with a good reputation to take their place at short notice. We took a lot of trouble selecting the roof tiles and  we are particularly looking forward to seeing the tiles laid. The roofers are on site beginning of March after a small delay due to rain to do the counter-battening and lay the tiles.      The roof is a pretty simple shape so the roofers make quick progress. We are using plain clay smooth machine-made tiles made by Dreadnought tiles and supplied by Ashbrook Roofing. We found out about them at a self build show we attended and have had great support from both Dreadnought and Ashbrook. We are using two colours - 70% staffordshire blue and 30% blue brindle mixed randomly. Before you know it, the roof is in place.     Big Day on 8th March as it is our first Air Test. We'd put 0.3 air changes per hour (ach) @ 50pa into phpp so we were hoping for something similar or better. Results were: 0.08 ach @ 50 pa 
0.11 m3/hr/m2 @50 pa Absolutely delighted with the results. Given building regs are 10 m3/hr/m2 @50 pa and Passivhaus standard is 0.6 ach @ 50 pa, this is over 90 times better than building regs and over 7 times better than Passivhaus standards and a great testament to the attention to detail shown by the build team.    Flashings between the wood cladding and the render are fitted. These were made by a Herefordshire based fabricator.      Work continues fitting the cladding. We are using Douglas Fir, supplied by Ransford which is literally 5 minutes down the road.      Once the roof has been laid and the weather allows, the rendering starts. We are using the Weber system, with a base coat applied first followed by a thin silicon based top coat which will be sprayed on.      The roof and detailing around the dormer window are completed            Once the cladding is complete and before the scaffolding comes down, we need to treat the cladding. The gable ends need a fireproof coating due the proximity of other houses, so it's one coat of primer, two of Envirograf and two of Osmo. The front and back of the house get one coat primer and two of Osmo. It's one of those jobs that costs more and takes longer than expected. We hadn't planned on having to to apply so many coats of product and in my naiveity I thought it would be a layer or two of fireproof coating on each gable.    The wood looks a little orange at the moment but that is typical when new and it does weather down nicely which is what I plan to allow the wood to do. Hopefully to osmo will help even out the weathering but I have no plans to keep on applying it.    The guttering is attached whilst the scaffolding is still up (Lindab galvanised)       The scaffolding on the house comes down and goes up on the garage to allow the roof to be completed on the garage. The second coat of render is sprayed on and the shell of the house is now complete.     

jonM

jonM

Building the Timber Frame

Having got all of the groundwork out of the way, it was time to build the timber frame. We were carrying out a stick build, ie: we purchased the i-beams and glulams and the carpenters cut and assembled everything onsite like a huge jigsaw puzzle. We had looked into using a timber frame manufacturer, but we had a good team of carpenters who had experience of stick building a frame, so it didn't seem to make any sense changing a proven formula.    Initial jobs were to get the scaffold up and sole plate down. First i-beams were installed on 3rd Dec and by the end of the day, the main i-beams for both gables were up.      The work is not helped by the weather which is cold and wet. You need to be pretty resilient to be work outdoors in this weather, nevertheless good progress is made and by 6th Dec the walls are up and parallam beams and ledgers have been fitted.      Big day on Dec 10th as we finally manage to get the electricity switched on. No more generators which should make everyone's life a little easier on site. We now have water and electricity on site and only need to connect to the mains drains at some stage in the future.    First floor joists together with the MVHR ducting that needs to pass through these joists is next to be installed and state of play on Dec 12th is as pictured below.     The first floor is glued to the joists on December 14th. The view from the top of the scaffold isn't bad either.    There is no way the big heavy glulam ridge beam is going to be manually handled up to the top of the roof, so on the 17th Dec a crane is hired to help out with this operation. It is the only time during the build that a crane is required. Everything else has been manually shifted into place.      The i-beam roof rafters can now be put into place and on the last day before the teams Christmas break, most of the rafters are in place.    Following a couple of weeks break for Christmas, the rafters are quickly finished off and by January 9th the skeleton of the house is in place.    Over the next couple of weeks the house is clad with panelvent on the outside and smartply on the inside    and then wrapped in membrane so that by the 22nd Jan, the house is looking like this.       

jonM

jonM

Groundwork and Landscaping

We make a start on 15th October with the diggers arriving on 16th October. By the 17th October, state of play is as per the picture below. The gabion wall on the right of the plot was put in by the vendor as part of the infrastructure works. The trench on the left is for a gabion wall that we are putting in on the other boundary. As there is quite a slope from back to front, we are putting another gabion wall across the plot to act as a retaining wall. All OK so far, but there is a surprising amount of muck that came out of the trench for the gabion wall which will need to be taken off-site. On the plus side, the plot had already been stripped of topsoil and as we are using a passivhaus foundation there was not too much extra muck on top of this.    The builder we are using has been involved since the early stages of the project. We didn't go to competitive tender but worked with the Architect to look for someone with experience of the build method we are using who we felt would be able to build to our budget. We are living around 3 hours drive from the site and made a decision out of necessity to continue working in our day jobs throughout the build, however we are purchasing all of the materials ourselves or via our own accounts which we expect will make the build more cost effective. This arrangement works to my strengths as whilst my practical building skills aren't great, I should be OK tracking costs and getting good prices on the materials.      Original plan was to get the gabion cages in place and fill them as time allowed, but the Passivhaus foundation could not be delivered for the requested date of 24th October, so once the drainage is complete,  filling the gabion cages becomes the main task to keep the team onsite busy. By 26th October, the majority of the drainage and gabion walls are complete     The following week is spent finishing of the gabion walls, landscaping, groundwork and preparing the grit base for the Passivhaus foundation. There is however a further delay on the Passivhaus foundation, so a decision is made to push on with the garage to keep everyone on site busy.      At the end of the week (2nd November), the slab for the garage is laid      The garage progresses quickly the following week and the Passivhaus foundation arrives on 8th November. There are some small dimensional inaccuracies with the Passivhaus foundation base that need to be corrected, but I am thankful this is spotted before the concrete pour when it is relatively easy to fix. It is however another delay and distraction we could have done without. On the bright side however, there have been no nasty surprises with the groundwork / drainage.     Work continues on the garage w/c 12th November with prep for the house slab starting at the end of the week. DPM and steelwork for the house slab go in on the 19th and 20th and following a review of the weather forecasts, we go for the 23rd November for the concrete pour. The concrete and concrete pump are ordered again, the rain holds off, temperature is ok and the pour goes to plan. Garage has also now been boarded.     

jonM

jonM

 

Getting to the Starting Line ...

An introduction to myself, my plot and and my self-build can be found in the following thread:   Having carried out one self build which turned out to be a lovely family home, we were keen to do another now that both our children had left home. We were drawn towards Passivhaus and started looking on the Southern side of the English Welsh border around 2015. The plot we eventually purchased was in Shropshire and one of 9 self-build / custom-build plots. The plots  have a design code but there is a lot of flexibility within the design code and energy efficiency is encouraged. All infrastructure work (roads, lighting, mains services etc) are being sorted out by the developer which removed some of the risk. Timetable to the start of the build was as follows:    Oct 2017 - Offer accepted on plot. Architect appointed. The architect was somebody who had already provided feedback on some previous plots we had looked at and we felt was very much in tune with our own ideas.  Feb 2018 - Initial Design completed. Pre-App submitted to planning.  Jul 2018 - Full Application submitted to planning Aug 2018 - Completed on plot Sep 2018 - Application approved by planning with one condition Oct 2018 - Started Groundwork / Landscaping. Planning condition discharged.    So, over 3 years from starting to look for a plot to starting with the build which seems to be around par for the course.    The house as mentioned previously is Passivhaus using a Passivhaus raft foundation and a timber frame that is being built on site using I-Beam / Glulam Beams. It is very different from my previous self build which was brick / block.   

jonM

jonM