Having given only a brief introduction to the building in Where it all Began, this post outlines in more detail the layout and condition of the building when we bought it, and basis for some of the overarching design decisions. Because the building had been repossessed at some point from a previous owner, there was no record of any previous maintenance or building work, and so we had to make assumptions and guesses about a lot of the building’s details.
The Setting
As mentioned in Where It All Began, the building occupied a basic rectangular external footprint of 12m x 8m when we bought it. There were gable walls at either end and a dual pitched roof. To the front, facing nearly due South, there were steps and a ramp elevating the façade and internal floor level to about 0.8m above the street. The land slopes uphill from the front to the back, and so to the rear, the building was in the hillside, buried up to 1.3m from the internal floor level. This meant that the gable window cills were nearly at ground level outside, but at about 1.2m inside, and the only access in or out was via the large glazed front entrance.
Layout
The building, as fitted out for its role as an office in the mid-00’s, had an internal footprint of 11m x 7m, and was divided into four segments, running front to back, by the roof structure. The building had a vaulted ceiling, 6m high at the apex, and in the quarter segments at either end of the building, the height had been divided into two floors, the central two quarters were single storey and open to the apex.
The main entrance opened into a wood cladding and glazed porch, which then opened into the “main space”. The main space, approximately 7m front to back and 6.5m left to right at floor level, was open up to the vaulted ceiling, occupying the central two quarters of the building. The timber structure of the roof was exposed, with the horizontal members of the main roof trusses spanning front to back, approximately 4m above floor level. The main space had no windows besides the large glazed entrance and one small rooflight in each segment of the north and south pitches of the roof. Along the back wall and from the middle of the right hand quarter, two wooden staircases ran away from each other to intermediate landings, and then turned towards the front of the house, providing access to the two upstairs areas.
A mezzanine floor, approximately 2.6m x 7m, formed the east gable upstairs area. It was separated from the main space by a glazed panel between the front edge of the mezzanine floor and the underside of the roof truss, and glazing set into the roof truss sections. It had no other windows, besides the small roof lights. Beneath the mezzanine, at ground floor level, a plastered wall ran from the front wall towards the staircase on the back wall, recessed 1.2m back from the overhanging edge of the mezzanine floor above. The space between this wall and the east gable wall of the building (another 1.6m beyond) was divided into three small rooms, with ceilings at 2.1m high, set up as a toilet, a kitchenette, and a disabled toilet. The kitchenette had a small window through the gable wall facing east, whilst the disabled toilet had a small window through the front wall facing south.
The west gable quarter was separated from the rest of the building by a floor to roof solid partition wall. A door opening in the centre at ground floor level provided access to the ground floor room. At approximately 2.6m x 7m and with a ceiling at approximately 2.3m, this room had windows through the front, west gable, and back walls, all of which spanned the ceiling up to the first floor room above.
Access to the upstairs room was via a balcony landing from the left hand staircase, and a triple-door-width glazed opening. The upstairs room was largely within the vaulted ceiling, with the sloping ceiling sections starting at just 1.2m on the front and back walls. The windows, corresponding to those in the room below, began at floor height. The windows were also short, apart from the tall window on the gable wall which extended to 1.8m from the floor level.
Materials and Condition
We knew from visual observation and some previous intrusive works that the walls were solid stone walls (random stone, rubble filled, about 0.5m thick), and were bare stone throughout most of the interior. They were generally in quite good condition, although had cement pointing (rather than lime) both inside and outside, and in a couple of places, had been patched with bricks.
The roof was slated. On the inside, the vaulted ceiling appeared to have a 40mm EPS (expanded polystyrene) backed plasterboard against the rafters, and mineral wool between the 100mm deep rafters. It was clear that the roof had undergone some remedial work at some point in the past, because the roof trusses had had new timber plates fixed to either side using large bolts. The purlins remained exposed. All of the visible roof timbers had been painted. The roof lights were by Velux, and dated 2005, which gave us a good indication of when the roof had last been maintained.
The ground floor appeared to be solid concrete with a black painted DPM, but we were unable to establish whether there was any insulation beneath the concrete. We thought that it was unlikely to have insulation, given the previous uses of the building.
The windows and front door were timber framed with double glazing dating from 2005, but the mechanisms were basic, the timber had warped badly and they had been poorly maintained (including evidence of chewing from the neighbouring cows). None of them closed properly, so they were very draughty. For security, all of the windows had strong, lockable, retracting grilles fixed to the inside, painted white. When these were closed, it gave the appearance of a prison!
The wall dividing the “main space” from the ground floor and first floor rooms adjacent to the West gable wall had been dry lined using gypsum plasterboard. We presume this had been done during the 2005 renovation, but there was now some evidence of damp, either from condensation or from rising damp, in the form of mildew and mould patches, and a musty odour.
The interior finishes were in excellent condition – the tartan carpet which ran throughout the building was of very high quality, and the interior joinery was contemporary and smart. The internal doors were the kind you find in offices, with a wire-meshed glass window, and toilet doors had ladies and gents signs on them.
Outside, the black plastic rainwater goods were intact and seemed to be operating properly. We found that surface water drainage was diverted into a soakaway rather than the foul sewer. Around the sides and rear of the building a tanking paint and drainage membrane was visible above the ground level and indicated that some drainage had been installed previously, but the extent of this was unknown without excavation.
The Design
The design which we eventually pursued was based on the information described here, as well as certain other factors, such as an obligation to improve the insulation in order for the building to be converted to a dwelling, the need for access from the house into the garden, a need for improved natural light and a view out, and our wants and desires for how the space would feel, flow, and perform as a home. The detailed decisions for how we handled various aspects of the conversion, extension and low-energy retrofit will be addressed in the upcoming blog posts, but were founded on the below design requirements:
Original Design Requirements
- Improve daylight and sightlines to outside
- Provide direct access to garden via new doorway
- Maintain open plan living space
- Provide additional storage area for bikes, tools, workshop space
- Upgrade energy performance to highest affordable standard
- Mitigate damp issues
- Retain front façade and (at least some) internal bare stone walls
- Improve flow and access through and around the building
- Optimise space
- Retain existing work as far as possible
- Work with a small budget
- Do work ourselves where possible
The Proposed Layout – First Iteration
The early drafts of the re-designed layout were based on the these design requirements. The layout was the first thing to work out, because that would then determine how we tackled other requirements like daylighting, insulation, access and flow.
The dominating factor for the interior was how to access both upstairs areas whilst removing one of the staircases, to open up the space on the ground floor. The total floor area was 115m2, however taking account of areas under the stairs, circulation spaces, and a storage cupboard, took it down to 93m2 of living area. The two staircases combined consumed 10m2, and whilst they provided possible storage space beneath, having two staircases consumed valuable living space. We therefore wanted to find a way to provide access to the mezzanine floor whilst removing the right hand stairs. Because of the style of the roof trusses, access was not possible through from the opposite landing, and nor would it be possible to put in another complete floor above the main space.
Building an extension on the back of the building could provide access through from the left stairs, across to the mezzanine on the right. If the extension was built to a reasonable size, it could provide additional living space, and be more than just a long corridor. Access could be from the left-stair halfway landing, and to the right stair halfway landing, so the room level would be part-way between the ground floor and mezzanine floor height. This would conveniently be at approximately the right level to provide an access point out to the garden. It could allow daylight in from the rear of the building, and also would bring the rear external wall into the thermal envelope, allowing easier thermal upgrades on the north façade.