In this paper three different structural alternatives (wooden frame, solid wood and concrete) for multifamily buildings are compared in terms of global warming potential (GWP) due to material production and bought energy-in-use from a life-cycle perspective using the ENSLIC tool [1]. The work has been performed in the pre-programming phase of a real construction project, aiming at achieving passive house standard and certification with the Swedish environmental rating tool Miljöbyggnad (MB).

The results suggest that the wooden structural alternatives are better in terms of GWP (1.8 to 1.9 kg CO₂-e/m², year) compared to the concrete alternative (4.9 kg CO₂-e/m², year). Having said that, there is considerable uncertainty in key input parameters in the calculation. Firstly, construction contractors in question could not supply standardized data for GWP and lifetime for their structural elements, and a combination of generic data and assumptions were used. Secondly, GWP for different energy sources was not available in such a way that it could be analyzed for reliability.

Mitigating climate change through operational energy reduction in existing buildings is of highest priority for policy-makers in Europe and elsewhere. At the same time there is increasing understanding of the significance of impacts arising from material production for buildings. The aim of this work has therefore been to evaluate the importance of embodied GWP for refurbishment for operational energy reduction on a stockwide basis. It is further intended to judge the relative significance of embodied GWP for specific refurbishment measures implemented for operational energy reduction. We study the case of operational energy reduction in the Swedish residential building stock by 50% compared to 1995. The total embodied GWP to achieve the noted operational energy reduction is 0.35 Mt CO2-e/year. 83% of this total is due to ventilation and window measures alone. Compared with previous studies assessing GWP mitigation from operational energy reduction, the "GWP payback time" is just over 3 years. Many types of measure that contribute significantly to achieving the above operational energy goal had average embodied GWP between 10 and 20 g CO2-e/kW h operational energy reduction, notably window and ventilation measures. Indoor temperature reduction (to 20 degrees C), was also significant for stockwide operational energy reduction but had a very low GWP of 0.4 g CO2-e/kW h operational energy reduction. If this measure proves unfeasible to implement on a stockwide basis then more expensive measures with higher embodied GWP will be needed to achieve the stated energy reduction goal.

In this paper, we propose a method for assessing renovation packages drawn up with the goal of increasing energy efficiency. The method includes calculation of bought energy demand, life-cycle cost (LCC) analysis and assessment of the building according to the Swedish environmental rating tool Miljöbyggnad (MB). In this way the methodology assesses economic, indoor environmental quality (IEQ) and specifically environmental aspects associated with energy demand of such packages from a sustainability point-of-view. Through MB, energy efficiency packages are placed in context with other necessary measures required to improve environmental performance in buildings, providing a consistent and systematic basis other than simply financial performance by which to compare capital improvements. The method is further explained and analyzed by applying it in three case studies. In each case study a multi-family building representing a typologically significant class in the Swedish building stock is considered, and for each building a base case and two renovation packages with higher initial investment requirement and higher energy efficiency are defined. It is shown that higher efficiency packages can impact IEQ indicators both positively and negatively and that packages reducing energy demand by approx. 50% have somewhat higher LCC. Identified positive IEQ impacts point to added value for packages that may not otherwise be communicated, while negative impacts identify areas where packages need to be improved, or where MB indicators may be referred to as specifications in procurement procedures.

The existing literature (mostly referencing heuristics of the valuation profession) provides little evidence on how property owners and managers themselves perceive value creation from environmental certification (EC) of buildings. To address this issue, questionnaire and interview data from non-residential EC building owners in Sweden are gathered and related in a strategy map' that explains their perceived value creation from EC. The mapping process also considers the four standard perspectives of the balanced scorecard, prompting researchers and owners to evaluate EC in terms of its contribution to long-term strategy, measuring it according to financial and non-financial metrics of organizational performance. The study confirmed that tenant demand is an important EC driver for property owners (particularly for large organizations) and therefore that increased EC awareness amongst tenants is important for EC and for further value creation. It was found that tool developers, property owners and valuers could all benefit from more closely aligning valuers' documentation requirements with those for accreditation with EC tools. Energy efficiency contributes significantly to value creation, but owners use energy management programs in addition to EC, possibly as a result of the performance gap phenomenon.

Previous research suggests that environmental certification (EC) affects rental rates in non-residential buildings, but there is still little understanding of how tenants differentiate such buildings from those without EC. This paper examines whether and how tenants perceive value creation in EC premises in Sweden. The findings (based on 29 questionnaire responses and 14 interviews with tenants in EC buildings) inform landlords and tenants on the development of EC strategies for improved organizational outcomes. EC creates value for tenants principally as support for their environmental management and reporting (e.g., low energy demand). EC is important for tenants internally, raising employee environmental awareness and improving employee attraction and retention. Tenants are generally positive about employee morale, indoor environmental quality (IEQ) and rental costs. However, it is not clear if such perceptions are dependent on features of modern premises in general, such as new fixtures, fittings and furnishings, and space-efficiency or from some EC-related feature. Tenants do not identify health or productivity increase in their EC premises. Findings suggest that the research focus should be shifted from investigating health and productivity increases through IEQ improvement to understanding the motivational improvement through value alignment with employees through EC.