TOWARDS ZERO EMISSION BUILDINGS: A Holistic Guide for Homeowners through EPBD Compliance and the Renovation Passport Framework

Abstract

This master thesis presents a suggested Renovation Passport for two typical 1960s single-family houses.
Following the recently approved Energy Performance of Buildings Directive (EU 2024/1275A), all member
states are to implement voluntary Renovation Passports by 2026, which will aid in reaching the 2050 goal of a
decarbonized building stock. The aim of Renovation Passports is to provide long-term guidance and information
on energy improving measures when homeowners plan for future renovations.

Energy simulations in IDA ICE were conducted for six locations in Sweden, in order to calculate the energy
demand reduction for the 25 different steps of building envelope improvements. Additionally, the impact of
installing different heat pumps and mechanical ventilation with heat recovery was assessed. Embodied and
operational CO2 emissions for all renovation scenarios were calculated, with the environmental payback time
and the investment costs presented.

Two renovation packages (BBR-standard and PH-standard) were identified as suitable based on Life Cycle
Assessment (LCA), investment costs, and practical feasibility. The BBR-standard was following the current
Swedish Building code, BBR29, for new constructions to reach the Energy Performance Certificate (EPC) class
C. The PH-standard was constructed to follow the quantitative building envelope goals for Passive Houses, in
addition to reaching the EPC class A. For the BBR-standard, multiple renovation scenarios resulted in the
desired EPC class, while the installation of a highly efficient heat pump being the single most effective measure
in reducing CO2 emissions and energy use. However, to reach the desired energy class and reduce the energy
demand, envelope improvements were needed, such as new windows, attic insulation, and added external wall
insulation.

For Building 1, the BBR-standard package yielded a 66 % lifetime emissions reduction, and reduced energy use
by 75 %, while the PH-standard yielded a 70 % lifetime emissions reduction and reduced energy use by 90 %.
The results showed similar trend for building 2, however, due to the higher form factor (envelope-to-floor ratio),
the PH-standard represented more embodied carbon emission, yielding higher lifetime emissions than the BBRstandard for the same building.

The proposed Renovation Passport is an interactive tool for homeowners to assess the data from this master
thesis on CO2 emissions, energy demand, energy use, and investment costs for each of the investigated
renovation measures. 22 500 combinations of renovation scenarios are available for each building type and
location, based on the homeowners’ preferences or need, making this Renovation Passport suitable for guiding
future energy-efficient and environmentally favorable renovations.

Popular Abstract

Popular science summary of the master thesis: TOWARDS ZERO EMISSION BUILDINGS: A Holistic Guide for Homeowners through EPBD Compliance and the Renovation Passport Framework, by Jens Lundgren (2024).

The Renovation Passport developed in this master thesis is an intuitive tool to explore 22 500 potential combinations of renovation measures, tailored for two typical 1960s single-family houses in Sweden. This tool empowers homeowners to make informed decisions about energy saving renovations, contributing to a more sustainable future.

Building operations such as heating and cooling contribute to CO2 emissions, a major driver of global warming. In order to meet the goals of a decarbonized building stock by 2050, and by complying with the Paris deal, the implementation of voluntary Renovation Passports is to be introduced by all member states in the EU by 2026. These passports will guide homeowners in selecting renovation measures that decrease energy use and carbon emissions over the building’s lifetime.

Typical renovation measures for 1960s single-family houses were simulated in IDA ICE 5.0. Envelope improvements such as added insulation and upgraded windows and doors were analyzed. In addition, different HVAC installations (Heating, Ventilation, Airconditioning and Cooling), were considered, including different heat pumps and Mechanical Ventilation with Heat Recovery. The simulation input data was gathered through the literature review on building techniques and regulations in the 1960s. Simulation standards according to SVEBY and BEN2 were used.

Embodied CO2 emissions for all the added materials and components were calculated, in addition to the operational emissions for 50 years. This was later presented as “lifetime emissions” and made all renovation scenarios comparable. The environmental impact of different insulation materials was calculated, where the favorable option was cellulose insulation for attics, and mineral wool insulation for external walls.

The key findings show that the installation of a highly efficient heat pump, (Air-to-Water or Water-to-Water), was the most effective way of reducing energy use and lifetime emissions. However, the installation of a heat pump would not reduce energy demand or improve thermal comfort, which favors improvement of the building envelope.

One major challenge in generalizing renovation measures for a given building archetype is that not all buildings conform to these archetypes. This challenge was addressed with the construction of the interactive Renovation Passport. Multiple choices from drop-down menus are available for the homeowner to set up the Base Case building according to their actual building.

Energy savings are based on the extensive energy simulations output data from IDA ICE. In the Renovation Passport, investment costs, CO2 emissions, environmental payback time and the potential Energy Performance Certificate Class are presented in a user-friendly way.

The Renovation Passport equips homeowners with a holistic perspective on sustainable renovation choices, contributing to the broader goal of reducing CO2 emissions when renovating towards Zero Emission Buildings.

• author: Lundgren, Jens
• supervisor: Åsa Wahlström; Jonas Gremmelspacher
• organization: Department of Building and Environmental Technology; Division of Energy and Building Design
• course: AEBM01 20241
• year: 2024
• type: H2 - Master's Degree (Two Years)
• subject: Technology and Engineering
• keywords: Energy Efficiency, Renovation Passport, Energy Simulation, LCA, Zero Emission, IDA ICE
• language: English
• id: 9163715
• date added to LUP: 2024-06-24 09:04:00
• date last changed: 2024-06-24 09:04:00