Scenario 3

Contextual scenario – London build to rent, high Density development


Higher density developments, in locations close to railway lines that are funded by institutional investors is a key area of growth for new homes, first signalled in the Government housing white paper[1].

Long term investors want reassurance that these developments are going to be great places to live for decades to come and building them to the best possible standards in the first place will help to ensure this.  The financial sector also like independent certification as it gives them confidence, potentially allowing developers to access different (including Green) funding.

HQM provides the well-researched standards, licensed assessor network and established assessment processes to provide recognised ratings of quality and sustainability. HQM ratings can support reliable investment, meet aspirations in local communities (e.g. local plans) and allow customers to make informed decisions before they rent a property.

To give an example, this scenario represents a mid-level apartment within a high-density block that is being built to rent (BTR). It is located in central London on previously developed land and within walking distance to many public transport options and local amenities.

This scenario is meeting good levels of energy efficiency and has been designed to mitigate overheating risk and the high noise and pollution levels from its dense-urban setting.  These are key challenges for this type of development, and of major concern to ensure that it is a good place to live and therefore invest in.

These assumptions have been made based on typical standards met by similar new-build high-rise developments in London and using local standards such as the London Plan for the kinds of performance characteristics that would be feasibly required by planning and expected by consumers. Some assumptions may be more specific to London but most of them are expected to be achievable in many other dense-urban city locations.

[1] Ministry of Housing, Communities and Local Government (2017) Fixing our broken housing market. Available at:



  • Development is built on previously occupied land
  • It is within walking distance to excellent public transport access and numerous amenities
  • There is no significant risk to ecology arising from the development
  • Development provides medium-sized communal gardens with planting and management in line with local biodiversity guidance
  • Safe cycle networks are accessible to project
  • No private parking but access will be provided to a car club including 60% hybrid or electric
  • Ultra-fast (100mbs) broadband is available

Safety and resilience

  • Low flood risk site
  • Post-development surface water run-off will be limited to pre-development levels (as encouraged by the draft London plan)


  • Low overheating risk ensured using DSM (Dynamic Simulation modelling, CIBSE TM59) based on current and predicted climate weather files
  • Ventilation rates significantly beyond regulations, air intakes designed to avoid pollution and easy maintenance and controls
  • Good levels of sound insulation have been met using building elements registered with Robust Details Limited to minimise noises between apartments, including from: low frequency sources (50 dB or higher e.g. from amplified music), general living (58 dB or higher e.g. from speech) and impact noises (54dB maximum e.g. footsteps from floor above)
  • Good daylight levels will be achieved to all habitable spaces

Energy and water

  • Very good designed energy performance (better than Code level 4 energy requirements for Carbon)
  • An A-rated washer dryer has been specified
  • Very low NOx boiler has been specified for heating and hot water
  • Good water efficiency; estimated 110 litres per person per day and efficient water fittings using optional fittings standard in Part G of building regulations


  • A small proportion of building elements have been used that have responsibly sourcing certificates (more than 5% of points achieved – see technical manual for details)
  • Six construction products are covered by a verified Environmental Product Declaration (EPD)


  • Cycle storage have been provided – 1 per home
  • Good internal recyclable waste provided
  • Nationally described internal space standards have been complied with
  • 4m2 private balcony

Quality assurance

  • Early and seasonal inspection visits will take place 4 to 6 weeks and 12 months after occupants have moved in, to check the home’s systems are working well and any snags are resolved

Construction impacts

  • The Considerate Constructors Scheme (CCS) has been used and achieved on-site including the relevant parts required for 2 credits in HQM
  • Water and energy construction use monitored during construction works
  • Low site waste has been generated in line with a resource management plan (8m3 per 100m2 of GIFA) and 70% diverted from landfill (by volume)

Customer support

  • Ongoing support for residents will be provided by the landlord/building owner


‘Very Good’


Overall, this is a high-quality home that is achieving very good star rating and some key features for low running costs, health and wellbeing benefits and minimised environmental impact

Other standards and benchmarks can complement HQM including more specialised certification schemes and other industry methodologies. In this scenario, HQM credits have been achieved to complement the London Plan’s focus on overheating risk reduction (using dynamic simulation modelling, CIBSE TM59), low NOx boilers and high energy efficiency requirements.

According to this scenario’s assumptions, sufficient additional credits and key backstops beyond minimum standards have been met to meet the requirements (see general assumptions) for:

  • a 3 in My Cost including low/mitigated flood risk and water efficiency
  • a 4 in My wellbeing relating to: recreational space, indoor air quality, daylight levels, sound insulation, thermal comfort, ventilation rates and internal space.
  • a 3 in My Footprint including: managing impacts on ecology with long term management, energy efficiency equivalent to Code Level 4 or higher, water and site waste efficiency and a proportion of construction products that are responsibly sourced and supported by environmental product declarations.

The My Cost and My Footprint indicator scores could increase from 3 to 4 if this scenario met some missing backstops:

  • My cost: 4 credits in security and 7 credits for energy costs (this is different to the energy efficiency score)
  • My footprint: 2 extra credits for responsibly sourced products (increase points from 5% to 10%) and achieving 2 credits from a lifecycle assessment

A My footprint score of 3 represents a similar energy performance to that required for Code Level 4 or better. However, Code Level 4 energy only considers Carbon and HQM’s energy calculation considers primary energy and fabric efficiency, as well as a number of additional inputs from SAP and HQM tools that enhance the robustness of the calculation. This means that a home that achieves Code Level 4 cannot be assumed to be automatically meeting HQM’s ‘My Footprint level 3 backstop for energy. See here for details of how HQM’s energy calculation goes beyond SAP.