Teal blue graphic

District heating - five top tips for developers

Decades after district heating schemes became popular in parts of continental Europe, the UK is now beginning to embrace the concept.  Although some Councils - such as Southampton and Nottingham - have utilised district heating to meet local needs and strategic goals, district heating has not yet taken off across this country. 

At the moment only around 2% of the UK's energy needs are supplied through district heat networks but this is set to grow.  Councils (with a planning function) have increasingly decided to utilise district heat schemes by mandating their inclusion in major new developments as a key stepping stone to achieve carbon neutrality by 2050.

So, if you are a developer, what do you need to know and what steps can you take to ensure major new developments are as efficient as they are desirable?

Planning requirements

Many new schemes will be driven by the requirements of the relevant local authority through the planning system. 

Local authorities in urban areas are leading the way but it is important to note that paragraph 97 of the National Planning Policy Framework requires local planning authorities to:

"identify opportunities where development can draw its energy supply from decentralised, renewable or low carbon energy supply systems and for co-locating potential heat customers and suppliers". 

In addition paragraph 96 provides that local planning authorities in determining planning applications for new development should expect to:

"comply with adopted Local Plan policies on local requirements for decentralised energy supply unless it can be demonstrated by the applicant, having regard to the type of development involved and its design, that this is not feasible or viable".

For example, the London Borough of Newham's adopted Core Strategy (2012) contains Policy INF4 which requires applications for major development in the vicinity of an existing or a planned district heat network to provide for connection to that network. 

Prospective developers should be careful to understand what the planning policy requirements are of the relevant local planning authority as it may be required to connect into a district heat network.  This requirement could take the form of a planning condition or a covenant in a planning obligation. 

In the case of Newham, it has adopted a local development order which removes the requirement for certain elements of a district heat network - such as the pipework - to connect to an existing district heat network to obtain planning permission.  This should make it easier to retrofit existing buildings where such an order has been adopted. 

Design

Ensuring that the design of the network is 'fit for purpose' will be an essential step in ensuring cost control.

CIBSE has produced a code entitled: 'Heat networks: Code of Practice for the UK'.  Although the CIBSE Code of Practice is voluntary, it sets out certain minimum standards which can be applied to both new build and existing premises. 

Issues which have impacted on public perceptions of heat networks include:

  • cost transparency;
  • quality of heat;
  • concerns regarding metering; and
  • extent of control.

The CIBSE Code of Practice can help developers address these concerns by enabling stakeholders to establish requirements for each district heat network that ensure:

  • Plant rooms and networks more generally are designed for realistic demand factors (including levels of insulation in any new development);
  • Demand for hot water is based on realistic demand assumptions.

It is important to ensure consistency of design between the properties in the development and the district heat network.  By establishing realistic design parameters and challenging system designers to remove unnecessary contingency in the design process, it will be possible to deploy smaller pipes and plant and therefore reduce Capex and Opex.

Installation

The key to ensuring a sound installation will be the employer’s requirements.  Areas to consider include:

  • Insulation – has this been fitted where specified to the relevant standard?
  • Bulk meters – have they been installed at the correct locations and installed so as to facilitate accurate data collection?
  • System flushing – ensure the system has been flushed as dirty water can cause significant damage to systems.  This can result in increased maintenance costs and, potentially, reputational damage for the developer. 

Commissioning

To date the focus on commissioning district heating schemes has not been as sharp as it should be.  In part this is understandable, as contractors are incentivised to get the system signed off and handed over.  That said, whoever is responsible for the development moving forward (and/or is responsible for maintaining the system after acceptance) will have to live with the results of the contractor's work.   It is therefore advisable that suitably qualified specialists are present at commissioning of key systems and to carry out spot checks on other elements such as HIUs.

A key way to check that a system is correctly installed and satisfies the employer's requirements is through the metering system.  There will be individual meters in each flat and bulk meters should be placed at key points on the network.

In the absence of accurate, working meters and a coherent data set it will be extremely difficult to assess the performance of the system.  Therefore commissioning should only take place once all meters are fully operational. 

Commissioning should also assess:

  • Central plant – the district heating contractor must demonstrate that the flow and return temperatures on the network are in line with design requirements especially at part load, and the pumping strategy is working as intended.
  • Internal heating systems in individual properties – often overlooked, these both heat and resulting return temperatures should be accounted for when balancing individual heating systems - even at part load.

Risks after handover

If the developer is handing responsibility to a management company on or shortly after commissioning of the district heat network it should ensure that liability for any subsequent issues with the district heat network cease at the point it exits.  The developer should therefore ensure that the management company or ESCo has direct recourse to the contractor who installed the system.

A 'softer' issue for developers is to ensure that occupiers of the development understand how their heating systems work and how their bills are calculated.  Explaining in clear language what is included as part of any fixed tariff improves transparency and trust in the district heat network.

This publication is intended for general guidance and represents our understanding of the relevant law and practice as at October 2016. Specific advice should be sought for specific cases. For more information see our terms & conditions.


Insights & events View all