Where do I start if I have almost no data?

Start with the meter and monitoring inventory. Knowing what you can measure, and what you cannot, determines everything that follows and is usually achievable from existing records and a site walk rather than new equipment.

Will existing networks need dwelling level meters?

The draft Metering and Monitoring Standard sets out metering requirements including dwelling level metering. Installing meters in existing buildings with pipe in pipe risers requires invasive work and needs planning ahead of the applicable milestone.

Can I prepare before the final standards are published?

Yes. Establishing what your network is, what you can measure and how it currently performs is useful regardless of where the final thresholds land.

Heat Network Performance Measures and Monitoring

What each measure means and what the data is telling you

The current published HNTAS material sets out measures across network efficiency, distribution heat loss, supply reliability, flow and return temperature, and metering and monitoring. Each one needs particular information, and each tells you something different about what the network is doing. The current HNTAS measures The latest published material includes measures covering network efficiency, distribution heat loss, supply reliability, flow and return temperature, and metering and monitoring. What is measured How it is calculated Data needed Network efficiency Useful heat delivered as a proportion of heat generated Heat generated at source and heat delivered to consumers, over the same period Distribution heat loss Heat lost between the energy centre and the dwellings, as a proportion of heat generated Bulk meter at source and metering at building entry or dwelling level Supply reliability Proportion of time supply is available without interruption Interruption records with start and end times, and total supply hours Flow and return temperature Difference between flow and return temperature against design intent Continuous flow and return temperature measurement Metering and monitoring Meters present, reading automatically and reporting accurately Meter inventory, read frequency, calibration status and data completeness The published material sets thresholds against several of these, varying by network element and milestone. We show the threshold for a measure once it is confirmed against its published source. Government HNTAS guidance and published technical documents Guidance based on the latest published HNTAS proposals and technical documents. HNTAS remains under development and requirements, measures and thresholds may change before final publication. Last reviewed [date]. Network efficiency Efficiency compares the energy you buy against the useful heat your consumers actually receive. A poor figure tells you the two numbers are further apart than they should be. It does not tell you where the gap opens up, and that is the question worth answering. You need energy in and heat out, measured over the same period, at boundaries you can define. Existing networks often come unstuck at this first step, where the input is metered at the energy centre and the output is estimated, or the two readings cover different periods. A poor figure can point to plant running inefficiently, heat escaping from the distribution pipework before it reaches anyone, or a network running hotter than it needs to. The pattern in the data helps narrow which. Check the measurement before you check the plant. Confirm the boundaries and periods align, then separate what is happening in the energy centre from what is happening in the pipes. Those are different problems with different price tags, and treating one as the other is how networks end up replaced when they needed rebalancing. Spinview holds the input data, the output data and the meter inventory together, calculates against boundaries you have defined, and shows the working. Where the data will not support a reliable figure, it says so rather than producing one. Distribution heat loss Heat loss tells you how much of what leaves the energy centre never reaches the people it was generated for. On an older network with buried pipework and original insulation it can be a significant source of waste, and it stays invisible until somebody measures it. The measurement depends entirely on where your meters sit. A bulk meter at the energy centre tells you what went out. Without metering at building entry or dwelling level, you have no way of knowing what arrived, and the loss figure becomes an estimate dressed up as a measurement. High heat loss can point to degraded or missing insulation, high network temperatures, long distribution runs, leaks or problems in buried distribution. The location and pattern of the loss help narrow the investigation. Start by confirming the meter boundaries, then compare losses section by section wherever the data allows it. Where the loss cannot be localised from what you already have, temporary measurement can help narrow the investigation before invasive work is considered. Spinview connects meter readings to the physical parts of the network they represent, calculates loss across the boundaries you define, shows where measurement is missing, and holds the before and after when remedial work is done. Supply reliability Reliability is about whether heat is there when people expect it. The useful question is not how many faults occurred but how often supply was interrupted, for how long, who was affected and what caused it. You need records of interruptions with the time service was lost, the time it was restored, the area or consumers affected, the cause where it is known and the plant involved. Many networks have this information scattered across a helpdesk system, a contractor's job sheets and somebody's inbox. Patterns matter more than totals. Repeated short failures in the same plant point somewhere quite different from one long outage. Recurring faults on a particular substation or pump set are worth tracing to a component or a control setting before anything larger is considered. Group incidents by cause and location before deciding what to do. That will usually tell you whether the answer is an operational change, planned maintenance, a component replacement or something more substantial. Spinview connects incidents to the network, location and asset involved, holds maintenance history alongside them, and shows whether reliability actually improved after work was carried out. Flow and return temperature The difference between flow and return temperature tells you how well heat is being transferred as it moves through the system. A narrow difference can indicate that water is returning hotter than the design intended, having given up less heat along the way, though interpretation depends on the design and operating conditions of the particular network. You need flow and return readings at the relevant monitoring points, taken often enough to show what happens under different loads. A single reading tells you almost nothing. A trend across a heating season tells you a great deal. A poor differential is one of the more diagnostic figures on a heat network. It can point to heat interface units performing below design, bypasses left open, incorrect balancing, pumps pushing more flow than the system needs, or control settings that have not been revisited since handover. Where the problem appears matters as much as the reading itself. A poor differential at the energy centre suggests something systemic. One that only shows at a particular substation or riser narrows the search considerably. Spinview brings temperature data into the network view, shows trends by location, compares one part of the system against another, and takes you from an abnormal reading to the plant, drawing or maintenance record behind it. Metering and monitoring This is the practical starting point for most existing networks, because everything above depends on it. Metering and monitoring determine whether you can demonstrate performance at all. For every meter and monitoring point you need to know what it measures, where it is, which part of the network it represents, how often it is read, whether the data can be accessed and whether the record is complete. The gaps are often practical rather than technical. A meter exists but nobody knows what it serves. The data is readable only by standing in front of it. The building management system has the point but no usable history. Measurements exist at the energy centre and nowhere downstream. Two systems use different names for the same asset. There is plenty of data for running the plant and not enough to calculate a performance measure. Build the inventory first and map each point to the physical network. Comparing that against the data each measure requires tells you whether the next step is access to something that already exists, a new connection, temporary monitoring or permanent metering. Installing dwelling level meters in an existing building with pipe in pipe risers is an engineering programme, so it is worth knowing early. Spinview creates one view of meters, sensors and data sources across the network, connects them to the assets they measure, brings manual readings and connected feeds into the same record, and shows the gaps against the requirements they need to serve. When will existing networks have to meet the requirements? Government has not published the timings for existing network milestones. It has said that existing networks will have a significant transition period to get the right metering in place so they can prove performance, and that final performance thresholds will be set at a more permissive level than for new build, with time allowed to reach them. The Technical Specifications describe milestones that networks must meet after a period of time, without stating what those periods are. The published milestone structure for existing networks covers minimum performance and reliability thresholds including metering and monitoring at Milestone 2, Performance Improvement Plans at Milestone 3A, metering and monitoring for networks not covered at Milestone 2 at Milestone 3B, and the requirements for certification at Milestone 4. New build networks have clearer published requirements. An assessment pass is needed before design starts, before construction starts and before operation starts, with a further assessment after two years of operation. What any of this means for your network depends entirely on where it starts. A network with reasonable metering and sound plant faces a very different task from one with a bulk meter, no downstream measurement and no reliable performance history. That is the argument for establishing the baseline now rather than waiting for the dates. Read performance in context A performance figure only means something when you understand the conditions behind it. Energy use and network performance change with outside temperature, occupancy, operating hours, weekends, public holidays and the way a building is being used. Spinview can combine network data with wider contextual datasets, including weather, degree days, calendar and public holiday data, occupancy or space information where available, and other relevant external datasets. That lets you compare like with like. A colder month can be compared with a warmer one on a weather-adjusted basis. Buildings with different operating patterns can be understood in context. Networks across an estate can be compared against suitable peers rather than a simple portfolio average. Where spatial or remote-sensing data is available, it can add another layer of evidence, helping identify patterns such as potential heat-loss areas that warrant investigation. The method and source data remain visible, so the analysis can be reviewed. One measure. Every network. The same measure applies across tens or hundreds of networks, and the answer differs for each one. Spinview shows that across the portfolio, so a question like network efficiency returns how many networks can be assessed today, how many need additional data and how many need review. Open any network to see the information behind its position and what needs to happen next. Explore these measures for my network This guidance is based on the latest published HNTAS proposals and technical documents. HNTAS remains under development. Requirements, measures, thresholds and implementation dates may change before final publication. Last reviewed [date].