Reveal – Practice
Oak Tree House
The original project brief entailed the extensive refurbishment of an existing private house – a 1970’s traditional load bearing masonry and timber single storey building. Upon further investigation, it was clear that it would make more sense in every way – cost, efficiency and sustainability – to deliver a new building on old foundations. Investing in refurbishment would have required every part of the existing structure to be replaced or strengthened sequentially. We revealed a new plan: a new-build house on an old site, with minimum negative impact on the community.
The demolished masonry walls were crushed on site and used to make up ground levels for the raised external works. The rubble and brickwork were reused into landscaping, cutting down both costs and the volume of waste sent to landfill. The reuse of the existing foundations overall meant 68% less concrete, saving 23 tonnes of carbon.
The resulting new building is constructed entirely in timber using glulam frames and timber joists to support the ceilings, walls and cladding. The only steel used in the superstructure is for the connections between the glulams, bolts and screws used in the connections and diaphragms. The use of a timber frame further saved the project approximately 3 tonnes of carbon.
At Oak Tree House we revealed the opportunity to beautifully build anew on old structures, while enhancing the cost efficiency and sustainability of the final building delivered.
The Old War Office
An ambitious refurbishment, converting the site from redundant government offices into a luxury London hotel and residential apartments. The Old War Office is undergoing a transformation from a disused site in the heart of the city, to a place to welcome locals and tourists alike. The new site will feature spaces for local businesses and health and wellbeing, along with a grand new ballroom, leisure spaces, and generous parking facilities, whilst maintaining the historic character of the Grade II* listed building.
Our proposal showcased the site’s potential without any detriment to the existing structure, such as introducing new basements beneath the existing courtyards whilst mindful of the load-paths of the surrounding stone facades. The investigations showed that the existing structure could accommodate up to four additional underground storeys, unseen from street level and with minimum impact on the historic fabric. We revealed significant ways to reduce costs, using resource material efficiently.
A 21st century addition to the 11th century Grade I Listed Lincoln Cathedral, the Cathedral Connected project is a perfect example of how engineering can reveal the best way to accommodate both the past and the future of a building.
Given the building’s Scheduled Ancient Monument (SAM) status, a lot of consideration was given to thoroughly investigating the archaeological elements present on site, down to the Roman level, 4m underground. Using non-invasive technology to understand the full picture and avoid any damaging excavations, all possibilities were carefully considered. This process, in consultation with Historic England, spanned the better part of two years and resulted in an innovative compensated balanced raft foundation solution. The weight of the building, combined with the weight of the foundations, is equal to the soil that could be removed from the site, essentially delivering a ‘floating building’. With no net gain on the archaeologically significant soil, this ensures the place is conserved for investigation and appreciation by future generations.
Linked to the 17th Century Grade I Listed Sir Christopher Wren Library & Cloister and the newly refurbished Grade II Listed William Burn designed Old Deanery, the new building features a shop and café, alongside community rooms and education spaces, due for completion end of 2020.