Holiday Cottages Underway

So here we are starting a new and exciting adventure at East Cambusmoon. Three years ago we moved into our house, beautifully designed and immensely energy efficient, see here. We adopted a very low energy approach to the design and the construction detailing which focussed on significant levels of insulation, a high standard of air-tightness, strong passive solar design and a ground source heat pump for the heating and hot water, supported by a small PV array and mechanical heat recovery and ventilation. When we were at the design stage 4 years ago this approach was not widely taken but, even in the short time since we moved in, more people and architects are looking more broadly at how homes and buildings are managed environmentally. We joined the AECB and adopted their Silver Standard for energy use and carbon emissions. In truth the house has far out-performed this standard and even in the last particularly cold winter was warm all day every day at very low cost.





The main difference between the projects are that the house was a new build and the holiday cottages are a conversion of two very tired farm buildings. Notwithstanding our intentions to replicate some of the approaches we took with a brand new building we are very aware that we are renovating an old dairy and byre and will certainly be retaining the architectural features the buildings; the red sandstone which was quarried locally, the arch over the doorway and the window recess with wooden lintel. Here we are creating two adjoining holiday cottages, one of two bedrooms, one of four. As we are in Loch Lomond & Trossachs National Park we hope that some of the year-round visitors to this stunningly scenic area might like to come and stay in the cosy warm luxury of our holiday cottages. As you can see we're just starting the conversion works and we'll do our best to record the journey on this blog.

The building story so far has been one of rapid change. The roofs have fallen in and the rubble cleared out; in the stone building (which will have two bedrooms) the 'hole' for the sliding patio doors has been punched through and the stone stockpiled for reuse; in the larger unit, which was brick built in the 1950s, the walls collapsed so extra blockwork and labour will be required; floor levels were equalised as existing floors sloped. Then we get into the first stage of serious insulation - the floor. So much heat is lost through the floor, don't waste it!

In the past week 200mm of polystyrene and polyeurathane insulation boards have been laid throughout the buildings and on top of this will float 30 tonnes of steel and concrete in the 4 bedroom unit and 15 tonnes of the same in the two bedroom unit. Before the concrete is poured the underfloor heating pipes are installed; this is done by fixing the pipework (large diameter polythene pipe ideal for use with heat pumps) to the steel reinforcement mesh with tie-wraps. This approach works well with ground source heat pumps which have lower operating temperatures than the more frequently used shallow tray form of underfloor heating. The concrete provides the thermal mass necessary to stabilise the temperature and keep those cottages lovely and warm when needed.We're using Anderson Floorwarming for the underfloor heating, hot and cold water systems, installation of the ground source heat pump and solar. We are happily working with the same builder, subcontractors and architect as we did on the house so its nice to see familiar faces back on site.

Storms, the garden, the heat pump - bit of a catch up

Sunday morning was gloriously sunny so a couple of hours in the garden was fun. With work during the week and a wet n windy day on Saturday I've barely looked at the garden.
Behold - the ravaged spring greens aka caterpillar central. I've tried picking off the caterpillars and feeding them to the hens but in all honesty I don't think the hens like them; the hens easily demolish slugs and worms but perhaps these hairy black and yellow (cabbage whites) caterpillars aren't awfully tasty.


The ravages of Autumn....we've had some proper wild seasonal weather now; this is Loch Lomond on Saturday, looking more like the sea than an inland water. The changing stormy skyline looks impressive and its great having a refreshing walk by the Loch; but also nice to get home to a roaring woodburning stove and the cosiness of the house. Last night the heat pump switched itself to winter mode which essentially means its been consistently cooler outside now (ie the average outdoor temp including nighttime is below 10degC) so if the internal temp drops then the heating will come on in the house. For us we've set the internal temp to 20deg, although its usually 2 or 3 deg cooler upstairs where we have no heating.

Not sure if I'm pushing my luck by trying to sow a few seeds this late but 2 weeks ago I carved out three mini-plots with some old Aberfoyle slate and distributed spinach, sorrel and mispoona. The latter is a combination of mizuna and tatsoi; essentially an oriental style green which should work well as a salad or cooking vegetable. I tasted a few leaves today, it has a full buzzy vibrant taste like peppery rocket. So long as we get a bit more sunshine I think we'll get some pickings through October. Nothing ventured....

Other parts of the veggie garden are still in great vigour; we've just finished the courgettes and cauliflower but have recently started harvesting savoy cabbage. Brussel sprouts are forming nicely, the leeks are growing and of course the ever exuberant chard. Plenty of iron rich greens!

There's still plenty of colour in the robust calendula which seem to have survived the early Autumn storms. I do like this flower, its so simple, so happy. When I remember I pick a few heads and pluck then dry the petals; they make a good addition to a bath for relieving excema and dry skin. Even better when placed in a muslin type bag with organic porridge under a running tap - it really works.

Progress...

I must admit to being a little tardy with my blogs of late, not least down to the fact that our cosy holiday let has no broadband so onlin leasure time is restricted. But, after a solid week in the office I'm ready to knock off early for the wekend so here's a pictorial tour...!

Kitchen area; dining to take place where larch cladding and frames currently being machined (covered in plastic)

Entrance hall on entering front door and looking up; stairs to be against wall on left (to replace ladder!!!). Next photo shows view into utility room from kitchen - heat pump on right hand side with electrics/TV/SAT/DAB/Cat5e wiring all terminating on board on end wall (must work out what magic boxes to buy to distribute signals!)

Room with a view - our bedroom to be precise, and this is the ever changing picture that we will wake up to... Next photo is the hallway looking down.

Hello again after another week has passed in a flurry of activity. The weather has changed significantly for the better and it has been dry for nearly a week which is quite remarkable after at least a month of driving storms. We spent a lot of time outside at the weekend, I was planting bulbs and Steve was building the climbing frame. With the advent of fine weather after such a long spell of hibernation it seemed that many of our local friends were out for walks and cycle rides so popped by for a viewing and it was a real pleasure to have so much progress to show people.
The big event of last Thursday was the switch on of the heating system and by Friday the builders were over warm and had all the windows open. We were mightily relieved and feel quite chuffed that it is already performing so well - partly because some observers are unsure of our reliance on renewable energy so its good to have an early positive response and mainly because we're desperately looking forward to living in the house. The system is being commissioned tomorrow. It will be interesting over the course of the first full year in the house to see how the comfort levels change and what running costs we encounter.
We need to have paint colours decided and bathroom tiles purchased by the end of this week for the upper floor so feel slightly under pressure. The bath and washbasin are fixed in the family bathroom and most of the other goods are in our en-suite if not actually plumbed in. I'm collecting an alternative shower tray tomorrow whilst on the way to order the kitchen and utility room cabinets.
Externally the brickwork is complete and I think the rendering commences next week. There appears to have been a change from the early days when Steve and I thought we were getting a smooth white render and the current drawings specify wet dash. I think this is being resolved but to be honest I can't remember where we're at with this..........just about sums things up as we juggle house building needs with the business and family. Plenty of evenings of work for us and lots of scraps of paper and lists here and there.

Heat pump installation

Work started on installing our heat pump last week. We have specified a Nibe 1240-5kW - the smallest capacity they make - with integral 'tank-in-tank' hot water cylinder. It 's a very neat unit, being the same size as a 1.9m tall fridge freezer. The pipework next to it will be ultimately enclosed in a cupboard which will still have some storage space at the front, whilst allowing access to the pipes at the back if need be.

Specifying a heat pump uses the opposite logic to specifiying a combustion boiler, as it must be just undersized to operate at its most efficient when taking into account the building's heat loss and anticipated peak heat requirement. The reason for this is that heat pumps dislike being 'cycled' - switched on and off - and actually benefit from running for longer periods at a time than conventional boilers. In extreme circumstances where, say, there is significant heat and hot water demand (eg. Christmas with visitors!) then the heat pump employs an electrical element to supplement itself, but the trick is to set things up so this hardly needs to be used at all, electricity being a relatively high-carbon form of energy.

The unit is being installed in our utility room where all the pipes from the ground loop, hot and cold water, underfloor heating and 1st floor radiators/towel radiators terminate. The guys are making a neat job of connecting this spaghetti together and hopefully by late next week we should be in good shape to switch on and get some heat into the 40 tonnes or so of concrete which forms the floor slab.

As it happens one of the founders of the heat pump supply company - Ecoliving - popped round yesterday to look at our windows (he's building an extension to his own house!) and he told me that the heat pump even had a setting to dry the floor slab out over a four day cycle, this will be important before we fit engineered board flooring.

Anderson Floor Warming of Glasgow are doing all of the plumbing in the house using a German plastic/aluminium pipe system. Hot and cold feeds are fed to manifolds from which each tap is fed, thus reducing pipe runs. Also the hot water feed is circulated from and back to the hot water tank at peak use periods (controlled by a timer) such that when a hot tap is switched on, hot water appears almost instantly.

Apart from the plumbers, the rest of the guys on site have never built a house with a heat pump in it and we are all waiting in anticipation for switch on!

In amongst the quagmire, building rubble, scaffolding and general building site detritus we have signs promising the return of life to the land. There is very little planting to speak of here (so far) but the rhubarb last year was gigantic and gorgeous so its exciting to see new growth. If I get my act together I'll get some buckets over a couple of plants to force some early crop. However as its driving rain and howling wind just now and there's a huge dump of snow forecast it'll certainly not be happening this weekend.

Inside the building the heat pump is being installed. It is a heavy piece of kit and took everyone here today to move it into the utility room. We've agreed its final position and from there Steve and I can order the utility room cabinetry. In a few days time the heating will all be connected and set to work. It'll take quite few days to come through as the pipework is deep in the slab but this will help dry the concrete before we look to putting flooring down. It'll also help to warm the rest of the house. Before the electrician left earlier he switched the heat recovery system on as it is now in place. We're pleased to report it is silent in its operation.

Still raining in Scotland

Where to begin? Like many 'phone conversations and chats if you speak to someone often enough you catch up on lots of news but if you haven't spoken to them for a while you can't think of a thing that you've done. As we've been in our friend's house for a week and have now moved to a holiday house nearby we're not on the internet so blogging has been sporadic in the past 10 days. Activity at the farm has been considerable so we'll let photos explain where we're at.

One of the past day's issues is the internal wallhead height in the upper rooms. As the house is 1.5 storeys the trick is to achieve a well-balanced room which is usable without looking like a triangle and providing lots of awkward corners. The architect has proposed 1.55m wall head in the master bedroom but we personally have huge difficulties 'wasting' all that floorspace behind the joinery/plasterboard. The elevation shown looks west; here we've agreed with the joiner not to put any internal joinery on that side, other than boxing out the flue which can be seen, but to reduce the wallhead on the east elevation to 1.35m. This still entails the 'loss' of floorspace but provides proper walls for placing a bedhead against. The second photo shows the framework in place for that. On one of the landings we're creating an eaves storage cupboard. We're hoping to achieve optimal usable floor space and create a desirable room.

The second photo looks east and shows the framework now at 1.35m, this will be plasterboarded imminently.

Downstairs and the hallway looks a little less finished.

Tomorrow the heating guys return to start work on the heat pump installation in the utility room. Jim, the electrician is connecting the last elements of the heat recovery ventilation system upstairs and will then move downstairs. The wood burning stove arrives tomorrow and the final long lost window arrives. The slates were finished last week and look grand.

Heat Pump: Part 1 - ground loop

As previously mentioned we have opted to use a ground source heat pump to provide both space and hot water heating. With no mains gas, an adjacent field and the opportunity to design a well insulated house from scratch with underfloor heating, the heat pump was the lowest carbon and lowest running cost option for East Cambusmoon.

For anyone considering a heat pump for their own house there aren't that many situations where it is the most cost effective and efficient choice, and certainly if you have the luxury of a mains gas supply a high efficiency gas boiler, coupled with say solar thermal panels will likely be a lower capital cost and running cost option than a heat pump doing both. If not on mains gas, then the costs need to be compared to LPG or oil and the decision will largely depend on the type of heating distribution system you already have, ie. radiators or underfloor heating. For the same heat input to a room, radiators need to be run at a higher temperature than underfloor heating simply because the heat emitter is concentrated into a relatively small wall hung panel, rather than the entire surface area of the floor. The problem with heat pumps is that their efficiency rapidly decreases in proportion to the heating medium temperature, such that running small radiaors from a heat pump is a bad idea. This can be alleviated to a certain extend by increasing the size of radiators so they can be run at a lower temperature.

Then there's the heat collection system, in our case this being a 300m length of 40mm diameter pipe buried 1.4m underground. This particular aspect of our build was a separate 'client item' from the main build contract so Debs, me, Stewart the digger driver and £60k's worth of band new JCB set to for four days of hard graft to get this pipe buried in the ground to in such a way as to absolutely maximise every joule of energy that could be sucked out of it .....which of course would be continuously be replenished by the sun. In effect, a huge solar panel!

In designing the collector system, we followed the heat pump manufacturer's (http://www.nibe.com/) advice on pipe depth, separaton and layout. Our supplier (http://www.ecoliving.info/) also offered advice on site and once certain of our plan, we got cracking! We ended up digging three 40m trenches, each 2m wide and 1.5m deep at 4m centres. We also imported 35 tonnes of sand to cover the pipe below and above to avoid the possiblity of damage from sharp rocks when backfilling and to ensure good contact with the ground. Bfore covering and backfilling, the pipe was pressure tsted and to finish off, fed into the house via the 'slow bend' duct pipes already built in to the floor slab.