1907 Tullochard

Model revisions October 2019

The last version of this project opened the south side of the existing house to make a more formalised relationship between the house and the new garage/outbuildings on the other side of the driveway. It removed the curve and generally rationalised the structure for a more affordable roofing arrangement. Although this became a very buildable option of a design we were pleased with, the client decided to adopt a more frugal approach and decided to purchase a proprietary conservatory from a well known Scottish supplier.

Ground floor plan as at end of June 2019

The client was very attracted to the idea of the extension curving to embrace the garden, utilising minimal glazing frames. A form of diaphragm wall provided mass for heat storage, along with the solid floor. The intermediate wall spread the structural footprint, which helped with supporting the roof cantilever. A study area and wine cellar were in the brief and these were located on the cold side of the wall. The curve provided an end wall which allowed both sides of the wall to point north west at the hills.

To help reconcile the form to the rather basic and abrupt north elevation of the existing house and to provide shelter and to protect the cold wall, we showed a canopy roof, connecting the two back doors with cover. On the end of the extension there is a covered external area for sitting outside but out of the rain and to give a place for alfresco eating.

The glass wall runs by the garden "front" of the house to provide a thermal buffer zone with separating sliding wooden panels in the kitchen to allow some control of heat losses on cool nights. We looked at a separate underfloor heating circuit in the garden room which could be for heating and cooling, offering scope to use preheating of a new water store. Thermal solar panels were considered and probably would have featured in the design but we were asked to not spend time on active systems while the design is in such an early development stage. However, the chosen forms of heat and power and the insulation of the whole are important factors which cannot be isolated from an holistic design. We looked at the EPC relative to the RHI options and advised that making best use of the solar gains would be key to making sense of this design but improving the overall levels of insulation would be a sensible place to spend money and it would make more sense of the proposal if using a ground source heat pump.

The brief was to stretch the scope of the design and to work it to find the best outcome for cost, mindful that what we were looking at would probably be too expensive and we would need to use what we have learned in the process of designing this together to make cost-saving adjustments. For example, although our client was keen on the curve, it is evidently far more expensive to build on a curve than a straight projection. Also, the cost of eliminating heavy glazing frames would be disproportionately expensive with triple glazed units, Certainly, making the glazing curved would have added considerably to an already expensive glazing option.

Model as developed for the meeting on the 22nd June

With no specific budget in mind, we were asked to explore the possible options for creating a garden room which makes the most of the views to the mountains, works with the new garden landscaping and provides sunny living accommodation without reducing the sunlight which reaches the dining and kitchen areas. The opportunity to capture solar gains in such an open, south west and west facing site was significant and the challenge lay in maximising the outlook while managing the solar gains and heat losses.

Ground floor plan as developed for meeting 22/06/2019