Plus-energy house in Perthshire

“After 15 years living in, and renovating a beautiful Grade II listed Georgian house in Berwick-upon-Tweed, we decided we wanted a change. We had fantastic sea and river views from the house which was quite large and on three storeys, but with a very small and public garden. The location right on the North Sea was very windy and the house was draughty and expensive to heat.

Inspired by our frequent business trips to Scandinavia we decided we wanted to live in an energy efficient and warm house. We spend a lot of time in January and February in really cold countries like Finland, Norway and Sweden but inside the houses are cosy. They know how to build well-insulated and draft-free houses with triple glazed windows that can cope with the cold climate and are economical to heat.

We are in the fortunate position of working for ourselves and can base our home and office almost anywhere. I was born in Edinburgh and have family there, and Stewart is a keen salmon fisherman, so we decided to look for a building plot in Scotland. My parents have an old cottage in Perthshire where we enjoyed many holidays and loved the area so we spend a week in June 2011 looking around to see what building plots were available. We were very lucky to find this rural plot between Perth and Crieff with outline planning permission so easily. The plot is just under 2 acres and has a wonderful big view looking south across a wide valley to the Ochills. The planning permission was for a traditional Scottish build of single or 1½ story single dwelling with pitched slate roof. This was not really what we wanted to build but the location, surroundings and view were perfect so we decided to go ahead and make an offer which was eventually accepted and we completed on the sale of the land in May 2012.

We were not in a rush to build, but started work on the plans with a local architect. He advised us to stick with the outline planning guidelines of a fairly traditional exterior with pitched slate roof. Inside we could have what we wanted with a large open plan living and kitchen area and double height areas. We knew that we wanted to use renewable energy where possible and had decided on a ground source heat pump, solar thermal and PV panels. The original plans were quite complicated with a separate linked building for our home office but after involving a quantity surveyor to get an idea of costs we had a rethink.

We were planning a traditional block and brick built house probably with a main contractor, but when looking through a self-build magazine I read an article about pre-manufactured houses. It sounded such an efficient, fast and easy way to build. The thought of building a house open to the elements for months in Scotland had never been appealing and I had read many horror stories of self-build delays and spiralling costs but I did not know there was an alternative. I was previously under the mistaken impression that pre-manufactured houses were all standard set designs and I knew we wanted a house that was a bit different.

After doing some online research into pre-manufactured houses, and looking at various websites, I was drawn to Hanse Haus as well as one other manufacturer. I sent an email to both companies on a Saturday evening and to my surprise Christian Witke, the Hanse Haus representative for Scotland, replied within an hour. I sent our plans and we scheduled a call for the next day. Christian gave me a lot of suggestions and advice. One thing he suggested was a basement to take advantage of the sloping site and build into the hill. This was actually on our original wish list but we had been talked out of it as we were told basements were always problematic to build and were prone to be damp and leaky. Christian dispelled this myth and told me about another Germany company who specialised in basements and who had worked with Hanse Haus on many projects.

Shortly afterwards we arranged to visit the Hanse Haus factory and sample centre in Germany as it was just a short detour on our way home from a business trip in Denmark. We were given a tour of the factory and able to see the building process first hand. It was so efficient and precise and made so much sense to do the majority of the build in a controlled dry environment. The huge wall panels had triple glazed windows installed in the factory and even the outside roller shutters (another feature we really wanted) were pre-installed in the walls. We were also able to look around the show houses and picked up some new ideas and inspiration. The quality of the craftsmanship was excellent and everything felt solid and well made. We also looked around the sampling centre where you choose all the materials, fixtures and fittings for your new house. I am extremely fussy so was very pleasantly surprised at the huge selection of high quality products like tiles, wooden flooring taps even beautiful zinc gutters.

We next arranged to meet Christian on our plot and he gave us a more ideas and advice. He arranged for us to visit a new Hanse Haus being built in Inverness and meet the owners to hear about their experiences. We also met with Colin Armstrong, an architect based Inverness, who has worked with Hanse Haus before. He recommended that we concentrated on thinking about the kind of house we really wanted and not to focus on the restrictions in the outline planning guidelines.

This was great advice as we had made a lot of compromises on the original design and it was not really what we wanted. We decided to start the plans again including a metal roof, a lot of floor to ceiling windows to take advantage of the views and a basement. We wanted a contemporary house that fitted into the surroundings, Colin drew up new plans which we loved and submitted an excellent design statement highlighting the eco credentials of our proposed house and the use of natural materials. Although the house was two stories because we were planning to build into the hill our ridge height came out lower than that of neighbouring houses. We got planning permission consent without any problem in February 2013.

We put our old house on the market in early summer 2013 and accepted an offer in September the same year. The purchasers were not in a rush so we agreed to exchange contracts but wait for completion until June 2014. We signed the Hanse Haus contract in December 2013 and went back to Germany in March 2014 to select all the fittings for our ‘turnkey’ house. Knowing that all the build costs were fixed was very reassuring”. Gill Siddall.

Build

“We had a lot of problems with drainage to overcome on site as our clay soil was not at all porous, and being off mains sewage we needed a way of disposing cleaned effluent. We enlisted the help of a specialist who came up with a satisfactory solution involving 600 metre of pipework and drainage under a farmer’s field below us. Groundworks could begin and we started digging out the area for the basement and positioning the driveway. It was a busy summer organising water and electricity connections, building retaining gabion walls, drilling the boreholes of the ground source heat pump etc. Luckily we were able to rent our old house for 8 months whilst our new house was being built. It worked out perfectly saving us the hassle of moving twice and meant we could continue our business without interruption.

In August 2014, the basement was built, which took just 2 weeks. We were away on a business trip at the time so it was incredible to see it on our return. A few weeks later at 7am on 23rd September we joined the Hanse Haus team to wait for the first of four lorries to arrive from Germany with all the pieces of our house. The whole process was precisely planned and worked like clockwork. The lorries are packed in the right order so that each piece of wall is craned off and positioned methodically. By 10:30am the west and south walls were in position and the house really started to take shape, it was such an exciting and memorable experience. By the end of the day all the walls with windows and doors preinstalled were in position. The next day heavy materials like tiles and baths were craned into the correct areas of the house before the roof was lowered on in sections. By 4pm on day two we were watertight.

After that progress seemed slower, but there was a lot going on – electrics, underfloor heating, plumbing, making the house airtight and laying the floor screed. We had a timetable of what would be happening when and everything was on schedule. Over the Christmas break the floor screed was drying ready for tiling, decorating and floors to be laid. The house was finished inside by the end of February 2015 and we moved in on 2nd March.
We were very impressed by the Hanse Haus team from Germany; the 3 main builders were with us throughout the build. They worked so hard and were trained to do everything, nothing was too much trouble and the quality of their work was outstanding. Outside progress was slower, we finished the gabion walls, had balustrade fitted, laid tarmac on the drive, and finally completed the paving in Spring 2016. We then dug out a wildlife pond at the top of the field and seeded the plot with wild flowers and grasses, we are now waiting for these to start growing. We have enjoyed the whole process of building a house immensely. My only regret is not being on site as much as I would have liked, as we lived 3 hours away from the plot and had a business to run with frequent sales trips”. Gill Siddall.

Description of house

The entrance to the house is via a sweeping drive to the front door, which is located at the rear of the property. The front door gives access to a contained porch and separate WC. From the porch, a door opens up to the main living space of the house consisting of a lounge and dining area with open plan kitchen. This room enjoys floor to ceiling windows with a stunning outlook over the local countryside. There is a glass-fronted balcony to the side of the property and a large utility room and walk-in pantry is accessed through the kitchen towards the rear of the house.

There is a further bedroom at the front of the house on the ground floor with its own large circular balcony with glass balustrade. This bedroom also has an en-suite bathroom.

The lower ground floor (or basement) is connected to the ground floor via a stunning oak and glass staircase. The lower ground floor consists of the master bedroom with en-suite bathroom and a separate dressing room, a sitting room and an office, all of which have floor to ceiling windows enjoying views to the front of the property. There is a twin guest room, also with en-suite bathroom at the rear. A hallway giving access to the various rooms runs the width of the house and joins a stunning oak and glass staircase, connecting the lower ground floor with the ground floor.

“The house has triple-glazed tilt n’ turn windows and underfloor heating throughout. The interior walls are 12cm thick and the house also boasts the Hanse Haus solid wall system, which combines the advantages of timber SIP and solid wall construction. The walls have a stud every 300mm (maximum) and they are completely glued on both sides with OSB boards. This allows all walls to carry the load of fixed wall units, including heavy kitchen units for example”, says Hanse Haus architect Bianca Keil.

The exterior is finished with a white render and wooden cladding and the property has a split-level zinc roof. The exterior walls are 30cm thick. There are external, electric shutters on the windows.

Utilities, renewables and technology includes heating via a ground source heat pump and mains water. The house boasts a whole house ventilation with heat recovery. Walls, ceilings and roofs are insulated with a mineral wood product, Sto bonding external insulation on external walls. Solar Panels – the property has 40 PV panels, a 10kW system. (In the first year, the house generated 8969kWh of energy. Its owners used 7791kWh, giving a surplus of 1178kWh). Chemical-free – only the roof rafters and the battens were impregnated with BOR salt to protect the wood against humidity, otherwise, no wood preservation was used and all materials are chemical-free.

Sustainability

Consisting of a timber construction, and given that wood has the lowest energy consumption and the lowest CO2 emission of any commonly used building material, the main structure of the house can be described as energy efficient. Added to this, the short construction time on-site meant that there was minimal disturbance on the surrounding environment.

What did you learn from the build experience?

“We learnt a great deal. Firstly, it pays off to plan as much as possible in advance. If you play around with the design in the early stages, you can be sure to get exactly the house you want. We found it was really important to think about how we were going to use the house to suit our lifestyle. This includes thinking about the flow within the house and how the different spaces interconnect.

Don’t under estimate the extent and cost of the groundworks and installing the utilities. We spent a lot of money on the drainage system and also the 3-phase electricity although in the end it was not necessary for the ground source heat pump but it did mean that we could have the 10kW solar system on the roof. We also spent a lot of money on the driveway and gabion baskets because we wanted the exterior landscaping to do justice to the house. Even if you go over budget, I think it’s important to stick to what you want if at all possible, we tried not to compromise and now we have a perfect house.

The whole process has been great fun and very rewarding. We’d do it all over again.”

Has your new home met your expectations?

“It’s exceeded our expectations – it’s just a wonderful house to live in. We love the height of the ceilings and particularly enjoy the main living room with open plan kitchen and dining area. The floor-to-ceiling windows make the most of the beautiful views and even the smaller windows frame the scenery a bit like a picture on the wall. The house really works with its surroundings. It also has a very quiet and calming atmosphere. Because the house is so well insulated we have a constant warm temperature and it is completely draft-free, of course!

Perhaps most excitingly though is the fact that we are generating more electricity in a year than we import from the grid. Considering we are in quite a cold area of Scotland this is really quite something. With the feed-in tariff the house is actually making us money.

What are your overall thoughts on building with Hanse Haus?

“It’s been a fantastic experience from start to finish. All along Hanse Haus have done exactly what they said they would and have built us exactly the house we wanted. The finish is exemplary and during the official handover even the tiniest of snagging issues were found, all of which were things we would never have even noticed. They also worked seamlessly with the basement manufacturer and the local companies we used for the staircase and kitchen for example. We really can’t fault them.”

“Having lived in a beautiful, but very drafty old house, a contemporary and energy efficient house was especially appealing.  The stunning contemporary design, and the fact that not only does it cost us nothing to run but actually makes money, means that our new home has surpassed all expectations”, Gill Siddall.

Client: The Siddalls, Perthshire
Plot: 2 acres
House: 3 bedrooms, 3 bathrooms
Area: 311m²