But the group - formerly called Bovis Homes - revealed it was seeing pressure on building material supply, which is leading to delays and cost increases.
Vistry said it was "actively managing" the situation and that any cost hikes were being more than offset by surging house prices.
The firm said it was well positioned to meet full-year expectations, having recently upped its profits outlook amid the housing market boom.
In May, Vistry said annual underlying pre-tax profits will hit around £325m, compared with previous estimates of £310m for the year.
Greg Fitzgerald, chief executive of Vistry, said: "The group has had a very strong first half with a step up in completions, price increases, improved profitability and strong cash generation, all ahead of our expectations at the start of the year.
“These results would not have been possible without the hard work and dedication of our employees and supply chain, to whom I extend my sincere thanks.
“Market trends remain positive and we are seeing good demand for completions beyond the end of the Stamp Duty holiday.
“ There is some pressure across the material supply chain in terms of price increases and extended lead times, but we are working well with our partners to ensure successful delivery of our build programme and expect this position to ease through the second half. House price inflation is more than offsetting any cost pressure.
“With 93 per cent of forecast financial year 2021 units already secured, a significantly higher level than in prior years, we are well positioned for the full year and are positive on the outlook as the strategic benefits of the enlarged Group are starting to be realised."
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