PortZED
Projects / Mixed use
PortZED
Project information
Client: Harbourvlew Development
Project Date: 2012
Site Location: Kingsway, Shoreham Harbour, UK
Project Status: Concept Design Completed
Introduction
PortZED is a mixed-use zero-carbon scheme utilising the best in building design achieve a low energy demand development. The development faces South West Shoreham Port and will comprise of 52 residential apartments built over shops, offices and support facilities, linked by a recreational landscaped deck, and arranged as a terrace of six lozenge shaped buildings, separated by voids and partly occupied with renewable energy systems. The scheme provides s for a high standard of living and achieves level 6 of the Code for Sustainable Homes specification. The development uses a combination of high specification building envelopes, plus a large proportion of renewable energy devices to deliver high efficiency and the coveted ‘Code 6’ status. It will be a zero-emission, zero-carbon set of buildings and will encourage occupants and visitors to lead a climate neutral lifestyle.
This composition, set against the industrial port activates, and beyond to the sea, is already analogous to the Brighton & Hove city typology, mixing as it does heroic terraces with interweaves of architectural miscellanies.
Sustainability
The developments overall aesthetic does not take sole influence from the surrounding neighbourhood but is rather a result of new a visionary sustainable design. PortZED’s coastal location maximises the potential to harvest the wind to generate power and this has become an integral feature of the design.
Dominant sustainable aesthetic features within the development include:
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A large number of PV and solar thermal arrays to capture the maximum amount of solar energy.
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A balcony/sun space within each South facing apartment where PV panels will be incorporated into each of the balconies balustrade. In addition folding windows and solar thermal panels will enclose the sunspace.
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A gently sloping roof to accommodate a large expense of South facing PV arrays along with a further expanse to the side each set of sunspace/balconies.
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A large canopy between the buildings to provide shelter from weather and additional surface area for PV panels.
In conclusion. PortZED will make a positive contribution to the urban context through raising the profile of sustainable technology, which in turn will delight and inspire people.
Principles of scheme design
All commercial spaces are at street level, providing an attractive, active frontage at Kingsway. This in turn encloses the public and promotes security.
Protected open space allows for safe and comfortable circulation and entrance into, around and out of the site.
All outdoor decks have level threshold with each commercial space as a response to inclusive access into and around the open space. The decks also ensure that the development makes the best use of the site and its surroundings.
All buildings are orientated to make maximum use of South West winds for the passive cooling and southern sunlight for solar gain. Furthermore, the building orientation allows for attractive sea views and for maximum amounts of daylight to reach each space.
Key principles
The overall design has a good balance positive and negative space, allowing all outdoor landscaping features to link comfortably with indoor space.
Public Amenity Spaces
The promenade deck which wraps around each of the buildings provides amenity space and allows active frontages to each of the commercial units at Kingsway. The amenity space is partly below the PV canopies enabling the space to be used in inclement weather.
Solar Canopies
Provide protection from inclement weather therefore increasing the amount of time that the spaces around each building can be used for. Green roofs are incorporated for either side of the PV canopies.
Green Walls and Roofs
Provide protection from wind turbine downdrafts as well as helping to differentiate public / private space; from a security and business point of view this helps to define clearly who can see what and where.
Future Development
Design idea exploring the possibly of integrating the PortZED scheme into a future development of Shoreham Port; providing the opportunity to improve the landscape character of the site via vast green/sensory space.
PortZED Energy Strategy
PortZED has been designed to optimise all forms of renewable energy on a constrained urban site. It has been designed to generate a modest surplus of renewable energy each year so that over the life of the building, both the embodied carbon and the annual energy demand is met, resulting in no net CO2 emissions to atmosphere over the anticipated project life of over 100 years.
The energy strategy uses south facing building surfaces and roofs to optimise solar electric output and passive solar balconies to flats. It uses the wind flowing between the urban blocks to power near silent vertical axis wind turbines, and it uses locally produced woodchip from the Shoreham Port depot to provide a little top up electricity and heat from biomass. The biomass combined heat and power plant has been sized to meet the required top up thermal demand to avoid heat dumping ,and each occupant will only use their fair share of the limited UK annual national biomass quota. The building is only climate neural over its lifespan because it combines solar, wind and biomass. If one of the elements is removed – this valuable target is lost. This building has been carefully considered to provide the optimised balance between wind, sun, biomass and energy efficiency, and demonstrates how to build responsibly meeting the resource challenges of this new century.
The energy strategy for residential units in the PortZED project is illustrated below. High levels of envelope insulation and airtightness help ensure that space heating requirements are kept as minimal as possible. With these high levels of airtightness, mechanical ventilation is a requirement to prevent air inside the apartments from going stale. To prevent heat loss, a fan pumps warm, stale air out of the building via a capillary heat exchanger, which transfers up to 85% of the heat into the incoming fresh air.
High level of exposed thermal mas within the building enable the temperature to become more regulated as the building has high levels of thermal inertia. Energy hitting dense concrete surfaces absorbs this energy slowly during the evening and at night. This means temperatures are higher in the morning than they would have otherwise been had the building been constructed of more lightweight materials reducing thermal load.
In super insulated buildings, the main sources of heat are solar gains through glazing, cooking appliances, other electrical appliances and the occupants themselves. However, on days where these heat sources are not enough to maintain a pleasant indoor temperature, an air source heat pump produces hot water to a hot water cylinder, and a separate heating circuit pumps this low-temperature hot water through the dwellings via underfloor coils.
Domestic hot water is also provided from the hot water cylinder via the air source heat pump. The air source heat pump (ASHP) uses electricity from solar photovoltaic (PV) panels to compress a refrigerant, which increases its temperature which is then pumped into the hot water tank. Heat from the outside air is absorbed by the ASHP in this process, and the higher the intake temperature, the more efficiently the air source heat pump runs. ZEDfactory has designed this system to take heat from a combination of the outside air and the stale internal air which needs extracting anyway.
The sum of PV arrays has been sized so that the annual output of PV power will meet the demands of the ASHP’s over the course of a year.
Conclusion
By removing the biomass CHP, NOx emissions for the site have been removed completely, at the expense of having to source all power for the commercial units from the grid.
Over the course of the year, the levels of PV production proposed in this report would be enough to meet the demands of all space heating, hot water and regulated electrical energy loads for the residential units, with 11MWh surplus.
This 11 MWh could be used to offset the commercial unit’s operational carbon footprint, or to charge electric vehicles in the basement of charging points were installed there.
PortZED is an integrated system design attempting to deal with a range of parameters. To maximise the renewable potential for the site required providing a solution to a building that does not contribute to climate change, a singular system is not normally enough positive. With the removal of the biomass CHP from the scheme, the building is no longer energy positive, and will require energy from the national grid, albeit far lower levels than a similar development built to building regulations would.
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