David Sleath0:05
The first half of 2020, our centenary year, has been like no other period in the company's history. We've witnessed a global pandemic which has impacted businesses and individuals across the world. And on behalf of everyone at SEGRO, I'd like to pay tribute to all of those who have kept the wheels turning during this difficult time, whether it's the doctors and nurses or other key workers, or people working in shops and supermarkets, or indeed those in warehouses and delivery networks that have kept us going, and many of whom are our customers. We're really proud of their efforts and grateful for what they've done to keep us going with essential goods and services.
At SEGRO, we've worked hard to help our staff, keep them connected and safe, to support our customers. And we're particularly proud of the work we've done to help those in our local communities that have been badly impacted by the pandemic, with the launch, a month ahead of schedule, of the SEGRO Centenary Fund, which has been very timely in providing targeted and much needed support in those local communities.
Despite these uncharted waters that we've been operating in, SEGRO's business has performed very well. We've delivered growth, we've been resilient, and we're pleased that we're able to report this morning a 6.5% increase in our profit after tax and a 2.6% increase in net asset value. In recent years, we've positioned the portfolio to benefit from structural trends such as e-commerce growth. Those trends have continued to pace during the first half of this year, and if anything, they've been enhanced and accelerated by the impact of the pandemic.
And that's translated into good demand for space from occupiers. This has been reflected in a strong lettings performance with £33.7 million of annualized new rent secured in the period, by a continued high occupancy rate, and by an average 10.4% uplift on rent reviews and renewals secured in the period.
Our cash rent collections have been very good despite the disruption caused by the pandemic, and we stayed close to our customers and have been pleased to provide support in the form of reprofiling rent payments to a small minority of customers that needed that help. We have continued to invest for growth with £633 million of net investment in the form of asset acquisitions, development expenditure, and in securing some additional strategic land purchases.
The primary engine of growth and focus for our capital investment remains the development program. During the period, we completed projects that generated 358,000 square meters of new space. It will produce over £20 million of annualized new rent when fully leased up, and two-thirds of that space has already been secured through pre-lets and lettings. In line with our SEGRO 2025 sustainability targets, all of the developments we completed are expected to meet the BREEAM Very Good or better sustainability standard, or indeed the local standard that we operate in some of our other markets.
We have further mostly pre-leased development projects on site which will generate £45 million of additional rent when fully leased, with another £33 million of additional rent from near-term pre-lets which we expect to commence in the months ahead. So the development program continues to go from strength to strength. On top of that, we've added to the pipeline of future opportunities with the acquisition of two excellent strategic logistics sites in the UK big box market, and with the purchase of a well-located 34-acre industrial park right in our core market of West London.
It remains to be seen how the pandemic will evolve over the months and years ahead, and how Europe's economies will react and indeed recover. However, one thing that has become clear is that many of these structural trends that have been driving occupier demand for our type of space in recent years have been enhanced and indeed strengthened as a result of the pandemic. E-commerce penetration has accelerated markedly across all our markets. There's a renewed focus on modern efficient supply chains, and demand for data centers is also rising. All of these factors bode well for future demand both from occupiers and investors for well-located modern warehouses. So whilst we remain cognizant of the macroeconomic risks arising from the COVID-19 pandemic, and we're alert to the possibility of further measures taken by governments to limit its impact, we are confident in the prospects for our business in the months and years ahead. In particular, we anticipate that the combination of our substantial low-risk development pipeline, combined with the benefits of active management of our excellent standing portfolio of assets, should contribute to further our performance at the property level in the months and years ahead.
