You may find the following articles interesting:

- Future of Life-Cycle Assessment in a Smart and/or Sustainable World

https://www.researchgate.net/publication/338327265_Future_of_Life-Cycle_Assessment_in_a_Smart_andor_Sustainable_World

- Internet of Things and the Future of Life-Cycle Assessment in Smart World

https://www.researchgate.net/publication/325871906_Internet_of_Things_and_the_Future_of_Life-Cycle_Assessment_in_Smart_World

It would be interesting to know how new energy management technologies (i.e. SMART, IoT) have an impact on building performance and environmental conditions or how they interact with a number of existing, retrofit and new types of materials, given a LCA based approach. Might be too large for a single Ph.D. topic.

You can look at some forest product materials as sustainable building/construction material. Hemp or jut geotextile, or new wood engineered materials.

I agree with @ shaghayegh . Look for energy efficient and reduced energy consuming alternative materials and do a comparative assessment with traditional materials, perhaps in different geographies. Try including circularity aspect as well.

1. Tire Derived Aggregates (TDA) produced from Scrap Automobile Tire;

2. Foamed Glass Aggregate (FGA) produced from waste glass.

I recommend you to look for Topics concerning Geotechnical and Environmental Engineering at the same time to propose environmental friendly Geomaterials and Geotechnical engineering methods in light of global considerations to the environmental concerns.

I have the experience of research on Thermal and Mechanical Properties of the two above mentioned By-products produced from waste materials. They may be of your interest. Please check the references below to find more information.

Article Laboratory Creep Parameter Determination of Sand–TDA Mixture...

Conference Paper Assessment of mechanical and thermal properties of foam glas...

Poster INSULATING PERFORMANCE OF FOAM GLASS AGGREGATE (FGA) IN COLD...

Presentation Thermal Behavior of Flexible Pavement Containing Foam Glass ...

Presentation Insulating Performance of Foam Glass Aggregate (FGA) in Cold...

Poster Mechanical behavior of pavement structures containing foam g...

Muhammad Shoaib Anju Baroth Shaghayegh Kurzinski Cory Jensen Aryan Shahabian