Weaker trading since lockdown has forced the move which will affect staff in Aberdeen, Glasgow and Manchester.
Stewart Milne Group chief executive Stuart MacGregor said:“Over the last nine months, we have been developing new design standards, products and accelerated build programmes and investing in digitalisation that will make us more competitive.
“Our recent annual business plan process assessed the likely market demand in each of the housing markets in which we operate.
“As a result of this, we are combining our Scottish operations to ensure we have the right resources in the right places and can leverage the benefits of our newly developed consistent ways of working and standards of excellence in design, build and marketing.
“Regrettably, our restructure will impact on jobs and we are embarking on a consultation process which will put 60 – 80 posts at risk of redundancy in Aberdeen, Glasgow and Manchester from a total of almost 1,000.
“This is not a decision we have taken lightly, but one based on what is best for the longer-term future of the business, protecting the majority of jobs and ensuring we are better positioned for growth in the next five years.
“We fully appreciate that this is a painful process given the current economic climate where many more people are also facing uncertainty.
“We are committed to managing the process as efficiently, fairly and transparently as possible.”