AJ Specification case study: a family home uses local material to create a sculptural roof form
Caring Wood is an extensive country home for three generations of the same family, incorporating formal, communal and private spaces. Set in 84 acres, its brief was to embody the spirit of the English country house and estate in a design that would embrace its context and landscape, while providing a carbon-neutral response to climate change.
The design of the house is modern but with clear links to Kentish rural vernacular and local building traditions. The relationship with the landscape takes precedence, with the central core and four oast towers growing from the contours of the hill. The language of the oast house is manipulated to provide a contemporary passive environmental response that manifests itself as a sculptural roof form.
The project programme had three clear stages: groundworks, including access roads, quarrying for stone on site and construction of a lake; the main contract, incorporating the house and the estate manager’s cottage; and the landscaping, including woodland planting of over 25,000 mixed native trees, establishment of 20 acres of wildflower meadow and an orchard of 500 cherry trees.
Caring Wood engages in the dialogue of critical regionalism: progressive design practice infused with a spirit of local identity. This is a sustainable house for life, planned inclusively around an entire family and designed to evolve with them.
James Wright, director, Macdonald Wright Architects
Caring wood roof 0135 © heiko prigge
Source: Heiko Prigge
Start on site Autumn 2012
Completion Summer 2016
Gross internal floor area 1,500m2
Form of contract JCT Traditional
Architects James Macdonald Wright and Niall Maxwell
Excutive architect Rural Office for Architecture
Project manager Alex McLennan (groundworks) Macdonald Wright Architects (main build)
Structural engineer Price & Myers
M&E consultant Synergy Consulting Engineers
QS GQS Services
CDM co-ordinator Butler & Young
Principal designer Rural Office for Architecture
Planning consultant DHA Planning
Landscape design Spacehub
Approved building inspector Butler & Young
Code assessor Synergy
Acoustic design Neill Woodger Acoustics and Theatre Design
Sustainability consultant Conker Conservation
Main contractor Hague Construction (groundworks), Cardy Construction (main build)
Landscaping contractor Landform Consultants
CAD software used Vectorworks 2014
Annual CO2 emissions -6.77kg/m2
Caring Wood is a model of exceptional sustainability, with both main house and cottage achieving a Code for Sustainable Homes Level 6, and an EPC ‘A’ rating. The brief required offset of 100 per cent of all CO2 emissions associated with energy consumption. The form of the building was developed around a central courtyard with the array of ‘oast’ towers providing summer cooling by full house passive stack ventilation.
The roof was constructed from 150,000 hand-made peg tiles from Sussex, supported on a CLT structure with woodfibre insulation sitting within and over timber I-joists. The roof represents 80 per cent of the overall exposed building envelope, so particular attention was given to the layering of this element from primary structure up to rainscreen. Built to Passivhaus standards, bespoke robust details were developed for all fabric elements and interfaces in order to achieve a U-value of 0.09W/m2K to the pitched roofs. The thickness of the roof is almost medieval in scale, due to achieving such a U-value with natural building materials.
Other materials sourced locally included ragstone from a quarry in Maidstone for external wall cladding, coppiced chestnut cladding from Lewes, and terracotta floor tiles from Ashford.
Niall Maxwell, principal, Rural Office for Architecture