New green space

‘Greening cities’ has become a much-vaunted aspiration in recent years. The aim is supported by the London Borough of Hounslow (click here for link to their website), the Mayor of London and by central government, on the basis that it can deliver environmental and social benefits.  

In the case of this proposal, the consideration of greening was further prompted by the significance of Kew Gardens to the project, and the theme has evolved alongside a growing understanding of how the pandemic has affected daily life. The result of this consideration is the provision of communal gardens at every third floor in the residential part of the building and within the ground floor entrance hall. 

These gardens provide a strong articulation to the elevations, and they are central to the distinction of the design of the building. 

However, more practically, they also provide space where residents can read a book, or exercise, and interact with their neighbours in an ad-hoc way. They provide a modern equivalent of a chat over the garden fence, or a private garden square, and are regarded as an important facility to help address stress and loneliness, the damaging effects of which are widespread and on the increase in our modern world. 

The design of the gardens is being led by award-winning landscape architects, Gillespies, who will ensure the suitability and longevity of the planting and the way in which the natural world weaves around the host building. 

The UK estimates a need for 1.5bn more trees, according to the government’s official climate change advisers, to suck up carbon dioxide and help restore wildlife. The Mayor of London has made a commitment to increase London’s existing tree canopy cover by 10 per cent by 2050. But how will this be delivered – Holly House provides 255 new trees.

The Urban Greening Factor (UGF) ensures development proposals contribute to the greening of London by including urban greening as a fundamental element of site and building design, and by incorporating measures such as high quality landscaping (including trees), green roofs, green walls and nature-based sustainable drainage.

The intend to adopt London Plan, policy G5 asks for a score of 0.4 for residential led developments. Holly House total score: 1.53. This is 3.825 times more than required to meet the policy - most developments struggle to meet 0.4.

Total internal and external greening: 3633m² (1.57 x the site area). This is 6 and a half tennis courts.

Total external greening: 3275m² (1.42 x the site area)

The Biodiversity strategy supports the Biodiversity Action Plan (BAPof Hounslow by increasing overall biodiversity of the site. 

Click here to open the action plan as a PDF

Holly House includes 960m² of vertical living walls.

There are a number of opportunities to enhance the site biodiversity and ecology and to mitigate the impact of the proposed development. These include developing a design that: 


Creates a Stepping Stone - Link into existing network of living roofs and  green spaces to form potential wildlife habitats and green corridors.


Provides a diverse Planting Scheme - Promote sustainable planting and incorporate  native and/or adaptive plant species into the planting designs with particular  focus on the priority species of Hounslow.


Introduces an Urban Woodland – Increase tree canopy coverage with understorey habitat creation. 


Includes Nesting & Roosting features - Incorporation of bird and bat boxes within the  existing tree network, and bee hotels on the roof. 

This strategy supports and encourages the key species of conservation importance which have been identified within the Hounslow BAP. 

Here you can see potential layouts of two floor levels and the roof. 

Next tile: Pictures

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