Shoreham Beach ‘Passivhaus LEB’

16 November, 2025 | General, Projects, Shoreham beach 'Passivhaus'

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Shoreham Beach House is located on a shingle beach on the South Coast in Sussex and the rear of the site has the enviable orientation of facing due south and having a beach aspect with fantastic views along the coast in both directions.  Architecturally the house faces south with the main living space on the top floor with a large terrace to make best use of the views, and with the first floor master and guest bedrooms with their own terrace.

About half the total energy used by a low energy building in it’s lifetime is the initial ‘upfront’ carbon used in construction, the ‘embodied carbon’, and so reuse of the existing building was considered, but was unfortunately not possible while achieving the design brief.  The form of the building is roughly cuboid resulting in a good surface area to volume ratio (Form Factor) and thus lower heat loss than a more complicated shape.  The site is at risk of flooding from the sea and so was raised 300mm and the ground floor and walls were constructed in waterproof concrete.  However, the upper floors switch to steel frame, timber infill and cellulose (recycled newspaper) insulation to minimise the carbon footprint.

The main technical criteria was to provide a low energy, comfortable and healthy indoor environment year round and the Passivhaus methodology was used to ensure this was achieved.  The building was modelled in the Passivhaus Planning Package (PHPP) which demonstrated a Heating Demand around 15 KWh/m2/yr (the target to meet Passivhaus).  Large areas of sliding doors were a fundamental part of the design brief, and it was assessed early on that this would make achieving the Passivhaus airtightness criteria of 0.6 ACH near impossible, as was proved to be the case with a (still very respectable) air test result of 0.76 ACH.  Interestingly, when the sliding doors were taped up as an experiment, a second air test achieved 0.48 ACH.  The building meets the slightly less stringent criteria for a Low Energy Building (LEB) as defined by the Passivhaus Institute, but is not certified.

The need to manage overheating drove the overall aesthetics of the project, especially to the south, with southerly overhangs to all three floors being achieved through the balcony, terrace and second floor overhangs, which were continued around the building.  High levels of insulation, sliding timber shutters to the south and west elevations, and cross ventilation designed in, all ensure excellent passive solar control and the PHPP modelling demonstrated minimal overheating.

See full details in the blog