Design and Planning
Initial design work started late in 2013, with the Feasibility study completed in February 2014. Passivhaus Planning Package, (PHPP) modelling of the scheme indicated that Passivhaus certification would be possible. After further design development a scheme was submitted for pre planning guidance in April of the same year.
This initial design tried to maintain the existing character of the barns as much as possible, with the brick facades retained, but with new openings added where required. Some dark cladding was included for the north elevation of barn B which was currently open and the roofs were to be finished in corrugated metal. The roof line of barn B was shown raised slightly to run through at the same height as barn A. Solar PV panels were included to the full extent of the south facing roofs on both barns.
Passivhaus, Dulwich Estate
The pre planning guidance received was not particularly supportive of the scheme. Concerns were raised about the extent of the additional openings in the barns, changes to roof line, roof cladding materials, enclosing the open north elevation of barn B and loss of agricultural character to the buildings in general.
The design was then further developed to address the planners concerns and after further pre application advice a more favourable response was received from the planners. Before submitting the revised scheme for a full planning application Cocreate Consulting were appointed as Passivhaus Certifiers for the project. A pre planning check by Cocreate provided further reassurance that certification would be possible.
A planning application was then submitted in March 2015 and approval granted in June with 18 conditions. The final approved scheme has a reduced number of window openings, maintains the original roof line with a slate finish but still includes PV panels to the extent of the south roof. The north elevation of barn B was set back behind the existing timber support columns but still clad in a dark composite cladding.