Report Assumptions and Structure

Introduction

Private outdoor space is a key part of a livable home, and has become a sought after amenity in a residential unit. The provision of balconies is not only an effective strategy for developers in attracting tenants and meeting amenity space requirements but it also has the practical function of providing access to the outdoors which has a direct correlation to quality of life, livability and mental health. Balconies have become private havens for people living in urban environments, and their value has been exponentially demonstrated in the recent pandemic where balconies have become a safe place to access the outdoors as well as platforms for community resilience and social connection.

In recent construction there have been many advances in building envelope performance but the balcony connection detail, and associated thermal bridging is often overlooked. The impact of thermal bridging on overall building performance has been the focus of numerous studies and reports but the design and construction industry has been reticent to address this connection detail for a number of reasons. As new building performance standards and requirements are introduced, the impact of the balcony connection detail must be considered to achieve the increasingly stringent performance targets.

Although relatively new to North America, thermally broken balconies are common place in other countries around the world. Northern European countries, which experience similar climatic conditions as Vancouver, have had to adapt their design and construction practices to accommodate similar advances in building performance requirements. Thermally broken balconies are now standard practice in these countries, which demonstrates the feasibility for this type of progress and innovation within the local industry.

To facilitate the transition to holistically higher performing buildings, this report focuses on understanding the impact of thermal bridging related to the balcony connection detail, its impact on the overall building performance, and provides a number of alternative solutions that address thermal bridging and allow for a more comprehensive improvement of the building envelope.

Report Assumptions and Structure

The approaches presented in this guide are relevant to balconies of varying material in buildings at varying scales; however, the primary focus of this report is for concrete construction for medium to high rise buildings. Building performance requirements are specific to the regulations governing construction in the City of Vancouver but the principles addressed are universally applicable. Refer to the local Authorities Having Jurisdiction for specific building regulations and requirements.

Both imperial (IP) and metric (SI) R-values are used in this guide for indicating the thermal performance of base building assemblies. Metric (SI) units are used when outlining thermal bridge performance values and regulatory performance targets.

This report is broken into three parts:

Part A: Understanding Balcony Thermal Bridging provides an overview of thermal bridging, balcony design considerations and common concerns regarding thermal bridging specific to the balcony connection detail. Part B: Balcony Types describes and compares several balcony construction options along with their associated benefits and drawbacks. Part C: Case Study presents a case study that compares the thermal performance of several balcony design options.

Part A