221005 MArys D&AStatement - Flipbook - Page 26
4.6 Sustainability
Overview
existing foundations.
The building has been designed to perform very highly
in terms of sustainability. The key measures employed
are:
This has the additional advantage of being able to
accommodate high levels of insulation and airtightness
very easily. The walls will achieve an U-value of 0.11W/
m2K. The windows will be triple glazed.
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Highly insulated and airtight building envelope
Mechanical ventilation with heat-recovery
Passive nighttime cooling
Retention of on site trees
Re-use of existing foundations
Energy
The building has been designed to achieve an energy
rating of A.
This has been achieved by using simple passive
principles and by employing the Mayor of London’s
Energy Hierarchy:
1.
Using less energy (Be Lean)
2.
Supplying energy efficiently (Be Clean)
3.
Using renewable energy (Be Green)
We will also enable occupants of the building to
monitor their energy use (Be Seen) though monitoring
devices.
Further details of the energy strategy can be found in
the Energy Statement.
We will aim for Passivehaus levels of airtightness, and
achieve this by lining the interior of the building with
airtight sheathing.
The exterior of the building will be clad with a soft, red
brick slip. The use of brick slips will keep the mass of
the building down and also reduce embodied carbon
further as they have reduced firing times compared to
a regular brick. The brick will be sourced from an
UK-based supplier.
Slimline Daikin Altherma 3 Monobloc 8kW air source heat pump
Lighting
The large windows and skylights will provide a good
daylight factor to all spaces in order to reduce demand
for artificial lighting. The skylights in particular will offer
uniform light to the spaces and make up for the
shading from the trees on the site. The building will use
low-energy LED lighting throughout, with an efficacy of
at least 110 lumens / watt. All lighting will be controlled
with absence detection to reduce energy waste.
Trees and planting
Heat and ventilation
The building will be heated by an air-source heat pump,
with the heat delivered via underfloor heating. The
building will benefit from the PV panels proposed for
the church roof, and already consented under a
separate application. All of the spaces will be
mechanically ventilated with heat recovery.
The two trees on the site will be retained due to their
ecological benefit and their positive impact on the
streetscape of the conservation area.
Embodied energy and materials
The form of the building has been designed in order to
give the trees at least enough space as the existing St
Mary’s Centre. In order to minimise impact on the
trees’ roots, we will reuse the mini-pile foundations of
the existing St Mary’s Centre, and only add new
foundations in the small areas where we are expanding
beyond the footprint of the existing building.
As a result of re-using existing foundations for 75% of
our building, we are able to keep our embodied carbon
levels very low.
The planting area to the south of the site will be
retained, and expanded around the base of the
southern tree.
Our proposed building will have a timber framed
structure, in order to keep the mass of the building
down to enable a two storey building to sit on the
Mary’s, Primrose Hill
The trees on the site bring important ecological benefit and contributing to the streetscape
Dow Jones Architects