It will also now allow for flexible construction types, self-build retention releases not linked to stages and independent self-build products.
Harpenden Building Society has revamped its self-build mortgage product through improved rates.
For loans between £75,000 and £999,999, a rate of 3.69% is now available and for loans between £1m and £2m, rates start from 4.19%.
Harpenden will also now allow for flexible construction types, self-build retention releases not linked to stages and independent self-build products.
Craig Middleton, mortgage sales manager at Harpenden Building Society, said: “Customers are looking to secure a dream property more than ever following significant time spent working and socialising at home during COVID.
"Property shows aired on TV during lockdown have also clearly inspired would-be self-builders too!
"We’re finding customers increasingly want to bring a highly personalised look to their new or enhanced properties, making a self-build project particularly appealing.
"With savings of 20-40% possible compared to buying a similar property on the open market, a self-build project is even more attractive.
"As a specialist provider our team anticipate increased applications, particularly with the new, improved product now live.
“As with our full mortgage range, we manually underwrite every mortgage application, allowing us to review each case in detail.
"Rather than relying on an algorithm to assess the application, like many high street lenders, we take a deep dive into an individual’s financial circumstances to assess even the most complex income streams – we want to reach a positive outcome and say ‘yes’!
"We look forward to supporting our intermediary partners as they use Harpenden’s improved products to secure new business with their customers – we’d be pleased to speak with any broker whose customer has a strong self-build mortgage application.”