Use stage, maintenance and material disposal
Poorly insulated dwellings have a large heating demand and typically use fossil fuels resulting in CO2 emissions, which are contributing to the climate crisis. 152 million houses in Europe must be upgraded or demolished by 2050 to meet the EU Climate Strategy.
Demolishing homes would mean the destruction of capital whilst building new dwellings would require the use of raw materials which, from an economic and an environmental viewpoint, is not preferable. Therefore INDU-ZERO targets sustainable renovation packages to upgrade homes rather than demolish them. We have already set out the sustainability of the product, factory and logistics in previous sections. In this section, we consider the sustainability of other aspects of the life cycle of the product: use, maintenance and material disposal.
The project applied a renovation package quality assurance procedure based on high resolution models of targeted dwellings before and after refurbishment as summarized in the following diagram. Note that such models can support performance assessments (via the ESP-r program) and constructability checks (via the Blender program), finally delivering part models to assist with factory machine programming.
The evaluation procedure used to confirm the energy-related efficacy of proposed upgrades is based on the ESP-r, open-source simulation program as developed by Strathclyde University with support under previous R&D framework programmes. Indicators relating to energy use, indoor environmental conditions, emissions and local low voltage network impact are considered under realistic operating conditions over annual periods. The approach enables performance assessments in terms of relevant criteria as summarized above and when assessed under a spectrum of weather influences and occupant behaviors.
The following table summarizes the predicted space heating energy requirement (kWh/m2.y) for 3 typical dwelling archetypes, under 3 levels of upgrade, with 2 heating system types, and under the influence of weather at 3 geographical locations.
Such results confirm that the INDU-ZERO upgrade panels make a significant contribution to heating energy demand reduction and, alongside other upgrade actions, can eliminate heating energy as a significant component. Underfloor insulation, where possible, delivers a major additional benefit. The next table shows the corresponding ‘net-at-the-meter’ data (= space heating + lights + appliances + cooking + hot water – photovoltaic supply), which evidences excellent progress toward net zero energy performance.
Summary observations based on these data are as follows.
~57/60/70%* reduction in DE space heating energy demand;
~74/75/84% reduction in ASHP space heating energy demand;
i.e. makes a significant contribution to space heating energy reduction.
With additional airtightness + MVHR:
~73/78/90% reduction in DE space heating energy demand;
- ~84/87/-% reduction in ASHP space heating energy demand;
- i.e. facilitated good progress towards net-zero energy.
With underfloor insulation (where applicable):
~95/96/90% reduction in space heating DE energy demand;
- ~96/97/-% reduction in space heating ASHP energy demand;
- i.e. near net-zero energy for terrace and semi-detached, especially in the Amsterdam climate. *terrace/semi-detached/apartment cases
The improved dwellings no longer need a gas connection, while most of the electricity will be generated by the houses themselves. This will result in a total reduction of 55.766.000 kg CO2 per year per 15.000 renovations.