Great House Farm

About this project

SIPs can hardly be said to constitute a new technology, having been in use in the UK in relatively conventional housing projects since the 1960s. Appreciation of their adaptability to unusual building forms is a more recent development, as is the ease with which their manufacture can be adapted to meet increasingly demanding thermal and airtightness standards. The simplicity and speed of the onsite assembly process has added to their attractiveness, with self-builders amongst their most enthusiastic users. The same might be said for those keen to build energy-efficient homes and communities at affordable prices, such as architects Gillard Associates Ltd. who, with Mulcare-Ball Developments Ltd, established LivEco as a joint initiative to create eight dwellings at Great House Farm (2015) in the small community of St Fagans on the west side of Cardiff.

The project is being developed in phases around the old village pond and within the historic field system, with the first phase designed to reflect the characteristics of the agricultural shed that previously occupied the site. Lifetime Homes and co-housing principles have been adopted here to help establish a sense of community, with open balconies and staircases integrated into the building’s structure to provide external amenity as well as private access to the mix of one- and two-bedroom flats, three-bedroom duplexes and a two-bedroom, single storey ‘pavilion’.

Use of Timber

The decision to use SIPs for the external wall panels was heavily influenced by the ambition to achieve a very low airtightness value (1.5 air changes @ 50Pa). The SIP block is effectively sheltered beneath a lightweight, engineered truss roof supported by full-height glulam columns. Thermowood® (See Chapter 4—the Modified Timber House) has been used to form the rainscreens to the external walls and has been open-fixed horizontally on the long, garden elevation; vertically on the long facade that fronts onto the courtyard; in horizontal louvred form to conceal the grilles of the MVHR units; and as open-slatted, vertical screens positioned near stairs and entrance doors.

Great House Farm is thus very much a hybrid of timber technologies in which a traditional load-bearing timber frame, SIPs and Thermowood® form the external walls, with timber frame open-panels providing the structure of the party walls in accordance with Robust Details. The intention in combining these different timber products and systems here has not been in the pursuit of innovation: the primary objective in this first phase of building at Great House Farm has been to deliver a rugged, low-maintenance and energy-efficient building envelope in keeping with its urban fringe, semi-rural location. This, and the fact that the low energy usage achieved here more than meets Passivhaus standards, demonstrates without fuss that modest increases in specification criteria over current Building Regulation requirements, together with attention to detail in the use of standard components, can deliver sustainable homes at the affordable end of the cost spectrum.

Further Information

The Modern Timber House in the UK, chapter 2

Images: Alan Gillard