Environmental and cost-effective refurbishment of million program building, integrating daylight and architectural design

Abstract

Sweden’s substantial building stock from the million programs is in need of renovations. These residential buildings were built without major attention to energy demand or architectural aesthetics. Until now, property owners have hesitated to carry out energy renovations due to the investment cost.

The aim of this master thesis was to propose an energy-efficient renovation procedure whilst taking into consideration sufficient daylight conditions and choosing materials with less negative environmental impact. Moreover, substitute the monotonous facades with a more appealing exterior. The case study building was a typical three-storey lamella house from the million program years, located in Landskrona.

The research methods of this report included primary research of on-site daylight measurements and observations, and research of literature studies. Furthermore, various simulation models within energy, carbon footprint, life cycle cost and daylight studies were developed and their results were analyzed to answer the research questions.

A retrofit package that accounted for cost-effective measures included: new low energy windows, new prefab lightweight external walls on the main facades, and insulated basement walls and roof. As a result the energy use was reduced by 50% and the heating demand by 70%. The most significant energy saving came from the replacement of the old windows. The energy savings alone did not pay off the investment cost. However, the co-benefits, gained from this renovation should be weighted into the decision making.

The co-benefit of sufficient daylight would lead to increased visual comfort that could further generate health benefits and increased productivity. The latter being especially important for people who work from home, as the flexible working hours are gaining popularity. Other tenants who would benefit from daylight in residential buildings the most, would be elderly; parents on maternity leave and kids; those on sick leave, among others. Thus, people who are exposed to daylight in residential buildings makes up a significant part of the society and should not be neglected of the opportunity to experience good daylighting design.

The results of the daylight study revealed that existing million program lamella building may have a favorable window to wall ratio for sufficient daylight design, however, there may be daylight oversupply in the kitchens.

Final renovation designs are proposed where the building was improved architecturally while delivering useful and sufficient daylight levels in all the rooms. The overhang study proposes the optimal shading device depth of 1.3 m and balcony depth of 1.5 m. The potential of home office adaptation was achieved, while the standard of Miljöbyggnad Silver was reached in 15 out of 18 living rooms.

Popular Abstract

Renovating residential buildings with environmental awareness!

Global warming is not a “Chinese hoax” and approximately 98% scientists today believe that climate change is caused by humans. Old, leaky buildings usually constitutes for a large energy demand that is often distributed by non-environmentally friendly sources, in a global context! We believe that environmental renovation is one of the keys towards a greener future, controlling the damage humans have caused!

Between 1965 and 1974 many houses were built in Sweden. They are referred to as the “million program” and today they are in great need of renovation. Nowadays, million program buildings are known for their monotonous box appearances and high energy demand. The environmental renovation method that is presented in this master thesis can potentially be applied to many more million program buildings, since they were built with similar construction!

We worked with an million program building, situated in Landskrona. The house was a three-storey building that sooner rather than later would undergo a renovation. The thesis focused on following parts: daylight conditions, reducing the heating demand, evaluating the climate impact depending on insulation and load-bearing materials. Finally, we looked at the architectural quality and the total cost of all the suggested renovation measures.

The envelope renovation would not only improve the aesthetics of the building but also make it more airtight. By doing the latter, the tenants would not need to use so much heating to compensate for the heat loss through the leaky envelope. They would also experience less draft and chilly floor caused by the thermal bridges at the balconies and windows. The new renovated apartments were increased in size and had a new, modern open-kitchen concept.

All materials have an environmental impact, from gathering the raw material to manufacture it and finally taking care of the waste in the end of the materials life-cycle. Depending on how the material was manufactured, the carbon emissions will vary greatly. The results showed that the commonly used insulation material EPS obtained 60 times higher carbon emissions than wood-fiber wool insulation. That was without considering that trees in fact also store carbon by itself. Trees are the carbon sinks of the atmosphere!

Nobody wants to spend their days in window-less rooms! The right amount of daylight generate health benefits and increases tenants productivity! There are plenty of people to benefit from good daylight design at their homes. Daylight was therefore examined in the existing lamella building. It was discovered that the building was well-lit however daylight oversupply occurred in the kitchens! That could further lead to visual discomfort and glare. However, the problem was solved with the implementation of optimal overhang depth of 1.3m. The optimal overhang design further resulted in an efficient shading devices as well as integrated external balconies!

All in all, our research raises the question and answers it. Can we renovate with environmental awareness? – Of course we can! This research delivers the method and tools to the industry on how to do it! Moreover we hope to help you to become more aware of the importance of preserving the environment surrounding you!

• author: Baumane, Aija and Dahlin, Lowe
• supervisor: Åke Blomsterberg; Niko Gentile
• organization: Division of Energy and Building Design
• alternative title: Environmental renovation
• course: AEBM01 20171
• year: 2017
• type: H2 - Master's Degree (Two Years)
• subject: Technology and Engineering
• keywords: Cost-effective renovation measures, energy reduction, renovation, million program building, LCA, LCC, Co-benefits, daylight, architectural design, shading.
• language: English
• id: 8918927
• date added to LUP: 2017-08-23 16:32:47
• date last changed: 2017-08-23 16:32:47