Last Thursday in the events space at art book publishers Fourthwall Books in Braamfontein, an exhibition of architectural works opened. Normally such exhibitions are reserved for late-career retrospectives and architecture biennials, but this one is different. It features just four buildings completed in the past two years by a Brixton-based architecture firm, Local Studio, which was founded three years ago by young architect and urban designer Thomas Chapman.The exhibition was curated by a group of jargony master's graduates calling themselves Counterspace, and doesn't so much pay tribute to past achievement as it attempts to demonstrate potential and, one imagines, through its own efforts, engender more of what's on display.Local Studio is quite unusual in that, while it's not averse to a house commission, Chapman focuses his attention on working for nonprofit organisations, often designing projects with a community and/or historical slant. The four projects on exhibition are a community centre in Hillbrow, a school in Tsakane, a memorial centre in Sophiatown, and a café at Constitution Hill.The Outreach Foundation Community Centre in Hillbrow was built with just R2.5-million - a budget better suited to a flat renovation than a community centre. It's a light steel structure clad in chromodeck, grafted onto an unfinished community hall built in the 1970s. If you think that sounds unpoetic, you'd be wrong.It's like a beautiful light box. Through clever contrast and the very grain of the building - the pattern created by the steel - it reflects something of the architectural texture of Hillbrow, but also stands apart as a landmark, as a building with a community function. Its highest point matches the height of the spire of the century-old Lutheran Church opposite in a subtle homage.Similarly, the Hill Café touches so lightly on the historically dense setting it looks as if it might sail away. At the same time, it delineates a part of the fort that was demolished decades ago, conjuring the ghost of a memory.Yet the extent to which each design can contribute to the urban social fabric around it is central to each project, helping to make safe, liveable public spaces.The Outreach Centre has a 12m window through which passers-by can see the dancers in its upstairs studio.Local Studio has pushed its projects beyond their budgets with some innovative fund raising, too. For the deck and roof garden at the community centre, they struck deals with various property developers in the area whereby they partially funded it in exchange for the right to use the deck, which has a strong relationship with the street, helping to foster a safe public space. For the recently completed Trevor Huddleston memorial Centre in Sophiatown, there's an Indiegogo campaign under way. Local Studio has designed a mesh sunshade for the building on which a map of Sophiatown will appear. Former residents will be able to place discs where they remember their houses being.In these modest projects they push hard for impact and meaning. Stripped of pretension, this small architecture studio has to rely on creativity and innovative design. Let's hope their 30-year retrospective lives up to these beginnings. Johannesburg stands to gain a lot.Additions and Alterations will run until the end of the year.Fourthwall Books, Shop No 5, Norvic House, 93 De Korte St, Braamfontein, Johannesburg...